Hi Dave;
Just some added information for you regarding a unit that Doug mentions in his post:
Serial 845 - No. 1 Heavy Repair Shop (M.T.), R.C.A.S.C.
Authorized under authority of: GO 71/42 - Effective 24 Dec 41
Disbanded under authority of: GO 96/43 - Effective 20 Jan 43
Excellent post Doug.
Cheers