I'd leave it original. If you want a 1909 to build on, seek out one of the 1909 rifles that the "wizards" at Century rechambered to .30/06 (actually .31/06). I just finished building a.22/250 on one of these for my boss. I've heard that accuracy on the conversions is an iffy thing. His rifle wouldn't do better than 4 inch groups at 50 yards, no matter what I did to it, so rebarreling was no big deal.