Master Mechanic Manufacturer Codes

[Lesserstore]

Today I was looking through some of my dad's stuff, and I found an M1250 ratchet, it says USA, but it's Stanley so . I also found a C16 1/2" nutdriver. I determined the manufacturers of the tools by comparing the MM tools to other manufacturers.
Latest updates in red.

C- 1983?-????: Vermont American- Nutdrivers and screwdrivers. The Master Mechanic models look identical to VA drivers. Maybe not even a code.

M- 198?-199?: Stanley- Mechanic's tools. Taiwan mostly, and the ones marked "USA" are questionable. The selector switches on some ratchets are patented by NHT (bought by Stanley in '86) and the mechanisms are very similar to those used by Stanley.

P- 198?-199?: Proto; ratchets; probably under Stanley ownership.

T- 1977-198? : Easco- Mechanic's tools. The sockets look identical to Craftsman sockets of the era and the ratchets were based on the RHFT.

If you have any more codes to add please drop a comment.

 

[Lesserstore]

Update 10/19/20:
P- 198?-199?: Proto; ratchets; probably under Stanley ownership.

 

[four.cycle]

So, who do you suppose made the slip-joint pliers? (I've enlarged the stamp as much as I could and pasted it into the upper right-hand corner.)
How about the adjustable wrench? Triangle Corporation? (That seems like kind of a no-brainer.)
These screwdrivers are also Vermont American as well? (I'm not seeing your codes in the ebay photos.)

True Value "Master Mechanic" MMTS4 4-piece tool set (photos ebay)

True Value "Master Mechanic" MMTS4 4-piece tool set (photos ebay)

True Value "Master Mechanic" MMTS4 4-piece tool set (photos ebay)

True Value "Master Mechanic" MMTS4 4-piece tool set (photos ebay)

Master / Master Mechanic / (private label brand of True Value Hardware) / manufactured by Easco, Vermont American, and (?) / https://www.garagejournal.com/forum/threads/master-mechanic.209646/ / https://www.garagejournal.com/forum/threads/master-mechanic-manufacturer-codes.465048/ /

 

[Lesserstore]

I wonder if the codes only applied to sockets, drive tools, and flat wrenches, and I was just wrong about Vermont American even having a code. I know that they started using all numbers without letter prefixes in the 90s or 2000s.