I'm not sure how this would look, but a fellow could get the longest sunshade made for the scope being used in a effort to gain the length appearance of the early scopes. Also painting it with a bronze color (not brass, too bright, shiny and pimpy looking), or an aged metal color that is not black.
There is of course always the option of getting an antique type scope and using that. It would require some ingenuity making up some mounts, but could make for a spiffy looking peice.
The thing to remember about the Buffalo Classic or Target Model is that these rifles are an attempt by H&R to cash in on the current craze for all things guns, duds and antyq's. While there was a break open design available in the old west, it was not a popular item and in the annals of gun history, thse take far back seat to rifles like the Spencers and Sharps, nor was it an H&R as we know it.
I would say to take the Buff' Classic you got and fix it up to suit your tastes, wants, desires and needs. The really nice thing about the long barreled Handis is that there is no incorrect way to dress 'em up, they look and shoot good in any period attire.