Vintage Hunter- I have the tig welder and mill, but such an option is "elaborate" and not "elegant".
Emri - The mechanics that you are describing would allow a sufficient force to move the cocking piece forward without the trigger being pulled. I will have to get another opinion before I consider your suggestion about the sear/cocking piece relationship.

Thank you all for your help. I think that option c) in the form of sleeving the bolt is the way to go.
I was trying to hint that D is not really an option. I am trying to gain knowledge by working on a "cheap" gun. Smart money would buy a modern rifle, rather than pay someone to work on this example.