Not too long ago, there was an informational thread on original dash ones (-1s). Since dash ones (-1s) will soon be C&R eligible, more collectors will likely gain interest in the relatively common models (the rare models already have a following). I wonder how many models this forum can account for. This post by Lee Jarrett can serve as a checklist:
It is not TOO complicated-
All the interesting Dash-1's are 4 screw, EXCEPT the 29-1's which are mostly 3 screw with the ONE gun exception.
The scarce ones:
First, only the CARBON steel (Blue & Nickel) guns in K and N frame apply. Forget the Stainless guns, J frames, and L frames.
Second, forget the 10-1 the 13-1, and the 53-1, which means something else.
So, the interesting Models are:
11-1
12-1 (check)
14-1 (check)
15-1 (check)
16-1
17-1 (check)
18-1
19-1 (check)
20-1
21-1
22-1
23-1
24-1 (check)
25-1
26-1 (not the 1988 reintroduction)
27-1 (check)
28-1
29-1 (check)
48-1
Some of these variants have never been observed, and may not exist.