Identify Safeties?

[bountyhunter]

I have three safety bars from SW revos and don't know why they are all different. I believe they came from:

60's era Model 10 (K frame)

90's era model 686 plus (L frame)

after 2000 (MIM) model 66 (K frame)

I would have thought the L frame one would have to be longer? AFAIK, none have been modified even though the middle one has a curved notch in the head.

Anybody know just by looking which is which?

 

[bountyhunter]

I guess I stumped the crowd.

 

[Tired Gunsmith]

j, k, and n used the proper r sized as frame size went up.
j-small
k-medium
n=-large