If no luck with just page 31, the whole manual, and the parts list is available from:-
http://www.royalsignals.org.uk/batteries-chargers.html
Charging Set E.D. 300W 30V(BSA) User Handbook, Jan 1961
Charging Set E.D. 300W 30V Illustrated Spare Parts List for Charging Set, ED, 300W, 30v, WO13438, Oct 1961