Hi,
You didn't make the deal of the century, but I think you did pretty well. The gun is an honest, well used, Mauser (with a broken ejector, but that is an unnumbered part that can easily be replaced). The black bottom FXO is nice and has it's own value. The holster and capture papers also look OK to me, so if you take the sum of the individual parts, you should be ok.
Rough estimate, I would say you overpaid about $500 .
But what is money compared to a complete original bring back rig?