Greg ------ Classic Guns charges $25. for a three day annealing job. It is well worth the small investment as your work will go much faster and easier. Quit killing yourself and send the lock plates, trigger plate and all avrews needed to attach to John Gillett at Classic. Once returned to you, reattach the plates with screws and have at it. You are right, The dirty diesel oil will gray the matal but much slower on cased material. Luck, Ken