My impatience has come to bite me in the rear again. After buying the parts I needed, I came across this auction and couldn't pass it up. It's a complete 151M stock. It even has all of the pieces I was missing to begin with...and then some. I'll either sell the duplicate parts and make some (maybe most) of my money back or go on the hunt for another project 151K barreled action.
http://www.ebay.com/itm/231863896541
http://www.ebay.com/itm/231863896541