I'm not an expert on the post 1970's black powder Colt's but here's what I remember:
The Second Generation models were actually made in Italy by Uberti, and assembled and finished here in the states,
I've heard stories that they were finished at the Colt factory, or at another American gun maker under contract to Colt. (Iver Johnson???)
The later guns were also made in Italy by Uberti, but the assembly and finishing was done in New York City by the John Jovino company, under a licensing agreement with Colt.
I "think" the Signature models were simply a late version of the Jovino guns.
Some of these Second and later generation BP Colt's appear to have higher values.
The original Second Generation guns from the 70's and early 80's have higher values than the later John Jovino versions.
From my observation, the Walker's, Dragoons, and SOME of the Commemorative versions of the 1851 Navy and 1860 Army have higher values than most of the other models like the 1849 "Baby Dragoon" and the 1862 Police models.
A cased set with the accessories adds value to any of them.
thank you wheel, i like the looks of the 51 navy. most i have seen are very well fit and finished but i have not personally handled a signature series gun.just wondering investment wise if the earlier guns are worth the extra c-note.