Kyt,
Have a look on this thread on one of the sites I work on. A donkeyman was an engine room rating who attended to the Donkey boiler amongst many other duties. Have a look here:
Donkeyman - Mercantile Marine
ss SAMVIGNA Liberty ship built 1944, official number 169914
Lease lend to Britain
1944 MOWT (Hain SS Co, London)
1948 USMC, laid up Mobile.
1960 Scrapped Mobile
Regards
Hugh