However, that just reminds me of the Norrell 10/22 that I passed on 2 years ago for $4100. There are quite a few of them here in his home state of Arkansas. Hindsight is 20/20. I think it would be a difficult task for sure. However, I think they would sell like hotcakes and you might even get a list of people that are interested real easily to confirm that the demand is there.
I called Vector recently - the guy said they tried to make a .22 drum but just wouldn't work out. He also said the .22 mags they have not would not be coming down in price because it takes a couple hours of labor to put them together. He did say they are making new .22 and .45 caliber conversion kits, so we'll all have to stock up on a back-up unit.