I guess it's not still in my stash, but I do remember an unusual rifle that came across my safe. A friend of mine called while I was in college and said he had a line on a mauser action that I might be interested in, as I was working on trying to learn how to build bolt action rifles at that time.
It was a genuine Mauser-built Spanish 1893, but it had been sporterized for hunting many years prior, with a beautiful monte carlo sporter stock, double set trigger, sporter barrel, modified safety, replaced bolt handle, scope blocks. The owner said it was a 7x57mm, I didn't really care, as all I wanted was the action. After seeing it, I thought twice about tearing it apart, but at the price, I bought it anyway. So I figured I'd see how it would shoot, then decide whether it'd be my donor action, or just another hunting rifle. I handed over $70 and was on my way.
I got it home, dropped in a round, and NO-GO!!! [beeep]? Didn't even offer to close. So then I panicked, what if it was an Ottoman? Guess it'd be a donor after all. So I casted the chamber, turns out it had been changed over to an -08 based case. So I dropped in a 7mm-08, closed clean. But to be safe, I slugged the bore, it wasn't a 7mm-08, it was a 308win, and my slug only had 2 HUGE lands on it.
So in buying what I thought was going to be a 7mm Spanish Mauser, I happened to have picked up a Mauser-built Spanish 1893 with a Springfield 2 groove barrel, for $75.
I threw a few rounds in the pack, took it out to the range and put up one of the best 5 shot groups I'd ever fired at that time. Then the best 10 shot.
So I went looking for an answer on who might have built it. I put out a few feelers with local smiths, made some phone calls, then a few weeks later, a fella called me up, said he thought he knew what I had and wanted to see it to be sure. He took one look at it and said he'd give me $400 for it. Not knowing anything, I countered with $500, he slapped 5 bills on the tailgate of my truck and we walked away. Maybe he was a fool for paying that much, maybe I was a fool for selling it that cheap, I don't know, and don't care - I made $425 on a 100yr old rifle without even trying to sell it.