Barrel… not lead, then what could it be?

https://www.midwayusa.com/product/4...nd-kit-1-oz-each-of-220-320-600-grit-compound

Wheeler Engineering Bore Lapping Kit.

I asked my GS if lapping would help a certain rare auto I have and his response was "Lapping can help most any barel". I wouldn't be afraid of lapping it. OTH, if he is going to sell it I might be interested, I had an AMT Skipper long ago and wish I still owned it. I'm not so picky about fit and finish on rare or unusual guns as younger people today are, I buy guns for their interest more than their perfection. PM me.