Sounds like a great little project. I've had a few Martini's... my favorite was a 17AI Bee, but if I were building another, I would choose the 22Rem Jet or the 256 Win Mag, just for the availablity of brass. I have one in 357, but it doesn't really turn me on. Its about like a Zulu blow gun !! I have one I rechambered to 32-40 and I love it. I shoot 120gr and 135gr cast... shoots way better than I can. Also had one in 218 AI Bee shot great, but brass was easier to get back then. Have and shoot a 25-20, but wouldn't choose to build in that caliber, as the neck walls are very thin.
I know you probably know more than me about all of the above, and in the end, you will make your own choice. Which is as it should be. Keep us up on where you go with it and how you are coming along. I know it will be something special.
John
