I agree with Old Tanker,
You have to know what you are looking at just like with any other Antique/Modern firearm.
Iver Johnson/Johnson & Bye opened their business with the 1873 patented early Defender/Tycoon/Favorite series spur trigger revolvers. So there are "many" antique & modern collectables manufactured by that company of early or late.
To begin with, You have to be able to identify or differentiate between an "Antique" and "Modern" example.
Several rules of thumb here. First is the grips. the Owl head must be slanted to the side to be "possibly" in the Antique Range. If the owls head is straight? It's modern. (See photo)
2nd, look at the barrel address. Early patent stamps are proof positive of Antique production. (See photo).
The model 1 has a side latch on the barrel catch. Then there is the "Swift" model (Worth a lot) and the early hammerless 38 with bulldog grips (Worth a lot). Any model 1 in 32 or 38 caliber is (Worth a lot). These are all pre-1899 models and collectors pay a lot for them if functioning and in nice shape. The model 1 bicycle guns (see photo) are (worth a lot) now and are very collectable.
I'm only touching on the subject. It's broad and because some folks see them "ALL" as junk? I've made a killing over the years....So, keep labeling them junk "Please".
Murph