Here is my model 19-3 4", s/n 9K93xxx shipped in February of 1978 and my 66-3 2.5", s/n BFP33xx shipped in December 0f 1990
The 19 was shipped after the run of dash 3s should have been over, but this is probably not a big deal, it is probably (?) among the last of the dash 3s.
Hope this helps with your project.
