Demolishing the front steps meant removing the handrail as well, with no tears shed; it was a plain wooden pole added in the 1990s, and we know from historic photographs that no earlier rail existed. But when we rebuild the steps, should we install another handrail, albeit something nicer? There was also pressure that decisions needed to be quick coming; if a support post was to be added, a footing had to be ready when the new concrete pad was poured just a few days later.
A conversation about the handrail was underway between contractor David Jessen, architect Mark Parry, and myself. We agreed that we didn't want to reuse the old "mop stick" handrail or replace it with a new but just-as-bad equivalent. Possible custom wrought iron rails were most often discussed; a thin black rod would be the less obtrusive option, for certain. But should it run along one side? Both sides? Down the middle? Have some curly decorative flair at the ends? Candice and I were simultaneously kicking around ideas for something fancier with both a top and bottom rail, either art nouveau grillwork or Roycroft-like Arts & Crafts ballusters between. Either might be period appropriate, but the debate itself was drifting away from the true question: what would architect Brainerd Jones have done?
Since Jones didn't specify a handrail, we could only guess what he might have done on these front steps, if it had been included. But in the rear of the house were two possible examples: the once-identical handrails for the kitchen porch stairs and the back stoop, both made of only wood and with Jones' hallmark "Union Jack X." Wouldn't he have used this same design in the front steps? I went further, and argued that such a rail would have been down the middle, rather than blocking the side wall/platforms, and cobbled together a crude Photoshop mockup of what this might look like.
Candice endorsed the concept, but our contractor objected strongly. If we were really restoring the house we shouldn't be introducing major new elements, such as a 4-inch-wide wooden railing. Plus, he insisted, the handrail would never have been placed in the center. "I'll bet I can find five examples of rails in the middle of steps," I pushed back. "Show me one," he challenged.
Since the Comstock House design is based on the shingle style country house of the 1880s, I looked first at houses designed by McKim, Mead & White, the most famous architectural firm for this school. Almost immediately, I found an example of a center handrail: The 1882 Isaac Bell House in Newport. But that was a simple metal pipe, and it wasn't free-standing - at the porch landing it terminated on a support column (not visible in this photograph). Only in the most technical sense was this a match, and search I might, no other examples could be found. Down-the-middle handrails rarely/never existed in the era, even expanding the search to late Victorians in general. Lesson learned: if you're lucky enough to have a contractor like David Jessen with decades of experience working on Victorian-era homes, pay heed.
But what did the old technical manuals say on the topic? Like shingle preservation and other obscura discussed here, the study of Victorian porch handrails lacked any easy Google answers. Turn-of-the-century carpentry books contained much on building stairs and handrails, but the focus was exclusively on construction of interior steps and 
fine joinery (gotta have a handrail punch to turn those handrail screws) and such complex craftsmanship as the geometry of making winding stairs. Rarely were exterior stairways ever mentioned, and never was found a discussion of center handrails. A passing reference to a center railing was found in the classic 1897 Practical Building Construction (which remained in print for more than thirty years), which implied using a center rail as a median divider when there was heavy foot traffic in both directions.
The period photographs also show that side handrails on entrance stairs began evolving -- and sometimes disappearing -- during the 1880s. Homes built in the Victorian Gothic Revival style usually had a first floor high off the ground, which required many steps; houses built during the Colonial Revival craze after the Centennial year were lower to the ground, with rarely more than a handful of steps needed. Victorian Gothic front steps were usually narrow and straight, almost like a chute; steps found on houses after that period tended to be much wider, and when there was a long distance to the front door, there were landings or switchback designs that broke the climb into shorter segments.
(Sidebar: After looking at hundreds of 19th century front steps, I've come to believe that Americans in the Victorian era mostly saw handrails as an aid to pulling themselves upward, not as a safety measure to prevent a tumble down. Examples abound of railing designs that would be be easy for climbing, but possibly dangerous for descending -- the rail is too short, begins at the third or fourth step from the top, is interrupted by a large newel post, and so on. Some academic has studied this to death, I'm sure.)
Above are details from a selection of examples from "Artistic Country-Seats" (1886, reprinted by Dover with new commentary in 1982) that show what happened to American front steps after the High Victorian era. In some cases, the sides to the stairs completely -- and dangerously -- disappear, but more often the sides evolved to frame the steps, integrating them into house design. 
In the middle example, the sides continue the spindle woodwork found on the porch balustrades. On the right, the steps are encased with a low wall that continues the shingling on the house, and is topped with a cap that could be used as a planter box or some sort of platform.
In the end, we were asking an irrelevant question: Brainerd Jones didn't neglect to build a handrail on the Comstock House front steps -- he did include it in his design, via a shorter and a taller sidewall that was completely appropriate to the 1880s style, giving visitors a bit of support while climbing the seven stairs. Or the two caps on each side could simply be used as a nice place to sit, which is exactly what the Comstock family did, posing for a snapshot during a 1937 reunion.