Colt SAA First, Second and Third Generation barrel thread specification

The barrel shank and thread specification for the first and second generation Colt Model P Single Action Army revolvers are:
Shank overall length: .699"
Length of threaded portion of shank (shoulder to breech end of thread): .580"
Thread specification: .695" x 20 tpi

The barrel shank and thread specification for the third generation Colt Model P Single Action Army revolvers is:
Shank overall length: .699"
Length of threaded portion of shank (shoulder to breech end of thread): .568"
Thread specification: ..683" x 24 tpi

All dimensions are nominal taken from actual examples.