I like the squareback TG very much for traditional purposes/looks, and I like it better than the round TG. I never had a problem with the SB TG on a Ruger Super Blackhawk .44 Mag like some have professed.
There is an old story about trying to please a certain Col. Talcott who had an obsession with the SB TG, and as Colt always was looking for a market/government contract for his guns, he kept the squareback TG on the 1851 Navy and the 1848 Dragoon until Talcott was courts-martialed for some offense. Shortly afterward, Colt went with the round trigger guards.
The Second Model Dragoon has the rectangular bolt stop slots on the cylinder and mainspring like the Third Model. I guess it is a matter of aesthetics. I don't have the money to delve into Dragoon replicas, but I appreciate any pics you folks want to post.
I wish Colt had made an 1851 Navy .36 Dragoon with the part octagon/part round barrel and a smooth cylinder. Here is my Pietta fantasy 1851 .36 Dragoon based upon a 2014 [CM] 1851 Navy pistol:
I think the pic could pass for a Second Model Dragoon replica if one did not know better.
I don't recall Pietta ever producing a Dragoon .44 of any type, only Uberti.
I apologize for intruding in the conversation.
Jim