^ I wasn't aware that Mustang even offered a ratchet in 1/4" drive! Both of my sets came only with a breaker bar, and there's no space in the boxes for a ratchet.
Do you see ANY difference at all on the Thorsen 77JC7E model? (I have always assumed those units with the extra letters/numbers after the part number were later production, possibly manufactured by National Hand Tools. Is that a "real" Thorsen or is it the Kilness-patent design? (on which they stamped the same part number, at least in the two NOS sets I bought from whatchamacallittools in Oklahoma City.)
Yep, there are Mustang 1/4 inchers, just not as common to find. Unfortunately many 1/4" versions of triple plays have been harder to come by, I just recently broke 200 1/4" ratchets, with 300+ each 3/8" and 1/2". Could be that Mustang 1/4" ratchets were offered as separate add-ons to the basic sets you have to keep the sets in the bargain price range they were most likely intended.
No, I don't see any major difference in the Thorsen (or Giller) branded Kilness ratchets from any other Kilness ratchet that came off the New Britain line. I recall conversations on other tool boards (like Mark KW's from many many years ago) that Thorsen had trouble getting their new factory up and running so they had to sub out some production to meet quotas - Giller is a .gov/.mil branding. Then there's the progression of ownership with NHT buying up NB assets and brands at the "fire sale" when NB went under, and apparently acquiring Thorsen a little later. That could explain the newer appearing Thorsen ratchets with Kilness pedigree.
For what it's worth, there are 3 slightly different shifter caps on (most) Kilness ratchets - the earlier and by far the most common version has a circular center with bars extending out 180 degrees apart (most of the Kilness ratchets I've pic'd so far). The second, much less common one that I've seen is a single bar that is slightly convex in shape - thicker and slightly taller in the center an tapering slightly to the ends (2 of the Thorsens). The third and least common is concave shaped - thinner in the center and thicker to the ends (2 of the Blackhawks). All of those caps drop right out when you remove the guts - there's a fourth version for quick release ratchets with a hole in the center for the plastic plunger cap. The earliest version is a tall cap that is retained on the handle by a ring inside (none pictured yet).
I've also noticed that suspected late production ratchets (possibly NHT and Stanley production, some with the less common shifter caps and brands not normally associated with NB) can have a sloppier fit to the guts, even NOS appearing or little used ones. I'm thinking the tooling was getting mighty worn by then and led to the demise of Kilness production, by that time under Stanley control after they swallowed NHT, in favor of cheaper-to-produce designs they already had.