Without pictures, that doesn't sound like too bad of a deal to me. I can't see why the tang would have been ground down. Ask the seller if you have any concerns. I buy stuff to shoot it, so if the bore is good, the action is tight, and you have full disclosure from the (presumably trustworthy) seller, I'd say you should give it some thought.
This spring while rolling through Billings Montana, I stopped at the Cabelas and was looking through the (interesting) used guns. There was a Borchardt there with a price tag of $1700. I asked the guy why it was so cheap. He told me it had a new pipe screwed onto it. A full octagon heavy Badger in .45-70. I would have scooped it up (and should have) if I didn't at the time owe the my government $1650 income tax.
![Cry :'(](https://www.cascity.com/forumhall/Smileys/cowboys/cry.gif)
The unaltered original next to it was priced a bit steeper. $6800. The damnadable misery is that it would have not been a problem getting shipped home to me as it is an antique in both sides of the border. I just couldn't take possesion of it on U.S. soil. Goes to show that the deal of a lifetime is only a deal if you can afford it.