[fred cook]

I believe that the "V" is Colt's "verified proof" mark from that era. If you could remove the barrel from the stock, you would most likely find other marks on the portion of the barrel covered by the wood. While the Colt rifles are not terribly rare and that one certainly is far from pristine, your offier at $400 may be a bit low. If you can, try offering to meet him at $500 (in the middle, so to speak) and see what happens. If you do managed to buy this rifle, resist all urges to "fix" anything. Don't clean the metal, replace the nipple, etc. All you would be doing would be reducing the value of the piece. It is what it is! Good luck!