Guy,
That's an older one and I'm not familiar with the detailed operation as I've never seen one in the flesh but have a few images.
IMG_20220223_194420.jpg
IMG_20220223_194448.jpg
1955 shrinker.jpg
The patent that I think covers that one is here
https://worldwide.espacenet.com/publ...&locale=en_EP# . I have the file but at 1.7MB is too large to upload to the forum. Maybe it needs a strip and clean. Probably need to check the patent against what you have to understand the detailed operation and assembly. The patent may have more or different information to what you have. The later jaws I have match the patent spot on in the angle details and other detail, only really differing in the oil grooves which are larger and in the underside of the jaws.