Springfield Trapdoor

A friend of mine needed to make some quick $$ and I took a Springfield Trapdoor off his hands for $300. Model 1873 stamped on top of breech block. (P) cartouche but the cartouche on the left side of the stock is worn and illegible. Rer ar sight is not the Buffington type.. Barrel has the VP Eagle head stampings and the bore is very good. Just wondered if someone might be able to chime in on the SN#85486...I used to access Springfield Research Service but that is no more. Thanks .

hopefully someone with more to offer will come along soon , my 1888 is a six digit so it puts yours early