Yikes...two words for you..."Beautiful Disaster". :-(
The spring used in the Lancaster/Perkes is a real bastard. I have a friend who right now has his Lancaster in the shop with this same problem. The man doing the gunsmithing is a very highly regarded, English trained (Churchills) "Jobber" on the east coast..so far he's 0 for 2 in making the spring and getting it to work. This "jobber" knows how to make springs. These springs are a "bit" different to say the least. Its a butt kicker of a job, no doubt about it. I believe the original quote for the job was around $1100. I have no idea what the final price will be.
I would think about sending the gun to a person who has experience in building and working with complicated mechanisms. Gunter Pfrommer comes to mind as does Abe Chaber. Gunters experience and learning his craft at Ferlach probably put this job in the "do-able" category for him. He knows complicated mechanisms and how to make parts for them. Abes very good too.
One word of advice....if you find a gunsmith to make the spring and it works...make sure you ask him to make some "blanks" that can be filed up and fitted if it ever happens again. Most gunmakers who craft complicated springs (think Purdey mainspring) make a few at a time.
Good luck.
Dustin
