Whatever happened on your 45-70 project? I have one that is nearly complete, needs extractor work. I picked up the barrel from Sarco (Gibbs old stock) and installed it on a No1MkIII receiver. Picked up the mag for it a while back for about $70, oh well. I did all the receiver opening with a dremmel, and the round feeds smoothly w/o the extractor installed on the bolt head. With the extractor, it grips the rim too hard and causes the round to twist just enough to impede feeding. I was expecting to need to modify the extractor, just hadn't got down to figuring it out. Have you done that step yet? Advice/pointers would be appreciated.
I used a bubba'd SMLE stock, and also had to open up the barrel channel to accommodate it. I am missing a couple of small parts that I need to track down, lost track of them over time, but nearly ready to go.