I looked at the Canadian Chipmunk documents that I have, for W&B information.
The 1950 civil DHC-1 manual specifies the datum as 42" aft of the firewall and the rigging position is set by levelling the canopy rails. There are no "Datum Points" or "Levelling Pegs". The CG range is -8.91" to -0.72", gross weight 1930 lb.
Nothing to do with W&B, but in the same manual, there is this tantalizing three-view:
The 1958 RCAF Pilot's Operating Instructions for the DHC-1B (EO 05-10B-1) specifies a gross weight of 2000 lb, but refers to another document (EO 05-10B-8, which I don't have) for W&B details.
Again, although not about W&B, these cartoons are worth capturing. Much more fun than the RAF's T10 documents:
The 1957 DHC-1B-2 Flight Manual is a civilianized, expanded version of an RCAF manual. The gross weight is 2000 lb and the CG limits are the same as the 1950 manual.
There are also a couple of new cartoons:
Finally, I have a copy of the 1968 CAF manual, but I have just noticed the W&B page is missing! There must have been a "sense-of humour loss" at DND headquarters, because the cartoons are gone, but there is a new, interesting chapter with Flight Test procedures.