Hi,
This is my first post here. Activated at last! Thanks.
Anyway, I have some answers and ideas about the pulley shown above.
I have one. It is also NOS, but is labeled with NATO numbers. I am pretty confident that it is a WW2 item that was re-stocked post war.
It is an Anvil brand. The '8' seems to be the distance in inches between the cheek plate pins.
And here is the part number listed in the Diamond T 969 parts manual, third item down.
I believe that this block is also correct for the M1/M1A1 Heavy Wrecker trucks. So now I am on the lookout for the single block to go with it. Then 300ft of 1" diameter rope!
Hope this helps.
Have a nice day.
Sam in Australia.