Al, I've seen a few martini rifles converted to 45/70 and if your project gets off the ground you ten actions for your first run may prove to be very popular. Unfortunately some of the octagon barrels I have seen installed look like truck axels and much is lost for the feel of a sportered martini. Many years I had a chance to buy a set of martini sporting rifles in the fitted wooded case with a few goodies such as screwdrivers, oil bottles and such. The dealer wanted $1000 for the whole set, but was willing to break up the set. Calibers were 303 British and old faithful 577/450 and a box of kynoch ammo came with each rifle. I had just gotten out of the navy and started a new job. That job paid all of $2.00 an hour. Guess I set my sights way to high as everytime I went to that shop they were still there. Beautiful wood, ribs on top of each barrel, barrel mounted sights.And the deepest darkest black/bluing I had ever seen. Darn tore my heart out as there was no way making what I was that I could never afford those two rifles. This was I believe in 1967. Wonder who finally ponyied up and got that beautiful set?. As a suggestion when your run starts offer up extra extractors in different rimmed cartridges 30-30,405 winchester, 38-55, 375 2 1/2 flanged express and possibly a few others. Would save cutting and welding the extractors and might just make your actions more saleable. Good luck with your endeavor. Frank