Thanks for your continued follow-up. We have found one additional reference to the 109th in Daniel Byers' article on Operation Canada -http://scholars.wlu.ca/cgi/viewcontent.cgi?article=1249&context=cmh
- on P40, which shows the regiment joining 5th Canadian Armoured Division in the assault on Delfzijl. The 109th's own War Diary records the regiment being "under operational control of 5 AGRA" on Jan 1, 1945; "under command 106 AA Bde and 3 AGRA" on Feb 5; and then taking part in Operation Veritable under 30 Corps. On Feb 19, the diary says they were under operational control of 2 Canadian AGRA and then, on Mar 6, under operational control of 43 Division. Six days later they were under command 106 AA Brigade before taking part in Operation Plunder. Then things get confused or, rather, VERY sketchily detailed, for the period from Mar 27 to Apr 25, with things seemingly incredibly fluid and fast-moving. From all this, we surmise that the 109th was very much a Canadian asset, and that they were moved around frequently as and where needed in the Canadian field of operations.
Sadly, the RA's own records and resources are not great (the website is terribly thin for usable info and their main archives are "in transit" to their new base in Salisbury) and we haven't found any other on-point resources, although Terry Copp, Dan Byers and Doug Jacobson have all weighed in with what little they know of the situation in this area.
As you can see, we are continuing to dig, and we are slowly closing in on Aschendorfermoor as the likely PoW/concentration camp in question as it most accurately fits the location and c.Apr 20 date, but we still can't be certain at the moment.
If you know of any other forums, RA or otherwise, that we might get help from, please feel free to say.