Thanks for your thoughts, however I do not have a 64-4. The other is a 64-5 and a 64-6 as stated in the initial post. I appreciate your comments though
OMG!!! For some reason I got it in my head that you posted "64-4." I guess I need new glasses.
Basically, on the 64-5, it was still "new yoke retention system on 3" and 4" heavy barrel" guns.
Doesn't change anything: Keep the 64-5.