Thanks Froggy,
It ain't easy being a lefty and wanting a lefty thumbhole for a right-action muzzleloader. I know that Richards Microfit will make me one like that but I dont want to go that route after all the feedback I've read from them. I measured the barrel channel at home (have a sporter size tupperware stock) and "it appears" as if it might work. I guess I will need to talk to them personally, I just dont want to leave a very thin forearm on a hunting rifle.