Tony and Keith,
Both the British and Canadian spare parts lists show extensive use of BSF threaded nuts bolts and studs. Both show the wheel stud as 'Stud, wheel, cone seating, no.3, part number TR162' and the nut as 'Nut, cone seating, wheel stud, No.4, part number TR203', but without specifying the size or thread. Sixteen of each are listed for the trailer. Both parts lists are later, the Canadian is 1943 and the Brit is 1945. Neither show a different part number for different studs and nuts for each side of the trailer.
I suspect this is because 1943+ manufacture limbers were equipped with RH threads on both sides. There was also a change order to retrofit RH threads on the left side of limbers already in service, but how far that went is not known to me.
The 25-pdr gun manual has a section on the ammunition trailer, as does the illustrated parts list. I am not aware of a manual just for the ammunition trailer. Reproduction manuals of good quality are available from Cavalier Books in the UK:
https://www.caliverbooks.com/bookvie...8cl30&id=19715
The cartridge case you are hoping to purchase is a British manufactured Mk.2 case made by the Royal Laboratories (Woolwich) in 1945. The CF means it was filled with a full charge of a smokeless propellant. There is no indication that the cartridge was refilled (no crossed out 'F'). The primer is a No.11 Mk.5/2, manufactured May 1953, but the primer filling date has been struck out for some reason, although the filling factory code and lot number have not. Nice find in any event, hope you can acquire it.
Mike