[Berkley]

This may help some:

Full patent here.
It shows the Cloverleaf House Pistol, which has a slightly different design of the cylinder lock than the New Line, but is the closest diagram I've ever been able to find. The New Line cylinder lock is at the rear of the cylinder rather than on the circumference:

 

[Berkley]

My apologies, I found another patent that has the diagram you need. I have never had any luck finding internal parts for the New Line. My only suggestion would be to get similar parts for the Colt Lightning from Dixie Gun Works, and try to modify them to fit. Here are the Lightning parts shown with the New Line patent diagram for comparison:

Good luck, and let us know how it turns out.

 

[Berkley]

That is a very handsome New Line! Not often you see case coloring like that. Congratulations.