The prices for high-walls have recently been the among the most volatile in the antique gun market.  Formerly prices in the upper strata would be for pristine pieces in higher grade configurations, but now it seems that the demand has outstripped the supply in the market.   

I would expect to see an asking price of anywhere from $2500-3500 and up for the rifle you describe.  Would it be a good buy at that price?  I honestly don't know, but that's what the asking prices seem to be.  The condition issues you mention would be glossed over by the seller by emphasizing the special features, and indeed they are a very desirable set of features, especially the sights.  If the bore is good and the SST works well, it might even be worth the price I mentioned.

As with all such ramblings, this is JMHO, and of course YMMV!

Green Frog

If you obtained a factory letter authenicating the rifle's original features and they are unmodified and the same today, it would enhance the value of your rifle.  The letters are available at:  (You need to Login or Register to view media files and links)
Phil