Added the coinmaster in 15056. Funny enough, my problems in implementing it were based on the fact that this is the first Sell shop that uses real items for the currency, and the first one that uses whichrow, rather than merging Buy and Sell into a single interface (which actually worked flawlessly with your changes).
Turning in peppermint tailings does not work yet, and I haven't really looked at how to make it work other than setting things up to parse a quantity from coinmasters.txt (using a format that I'm not all that happy with, now that I look back at it).
Turning in peppermint tailings does not work yet, and I haven't really looked at how to make it work other than setting things up to parse a quantity from coinmasters.txt (using a format that I'm not all that happy with, now that I look back at it).