Hi Malc
The nema flange designation would be the size of the square flange in inches so looking at the ones with gearbox I am guessing from your caliper Nema 34 and I would like a couple of those if possible .

https://www.kollmorgen.com/en-us/dev...ma-frame-size/

Difficult to see if the ones which you say you have only four are bigger or smaller but the square size of the flange would tell us .
E stops? yes please
Breakers? yes please
Are there any distinct drivers or are they incorporated into the machines boards?
Anything there that looks like a power supply? I certainly see transformers both toroidal and conventional.

Am thinking that the it would be good to have the opportunity to have what in Cumbria we would call a "ratch".
For those who do not understand our lovely dialect I am thinking of a rummage amongst the contents of the heap ,