222 and mag size extractors are not too hard to find. 308 size are hard. I have a 721 in 6mm that has an extractor which is less than perfect. I think, now that PD season is coming to a close, I'll try to bend it a little in hopes to get it 'right'. I think that the extractor has been modified somewhat in the past, (before bugger).
I too would be interested in a half a bag of extractors.
Gemby's price sounds very good.
I too would be concerned about gas handling capabilities of a modified bolt though.