As for the rest of it, I doubt any current serving member at any Armoury are well positioned, or qualified, to attribute the proper historical value of the items found. Remember that they serve in the present (like most of us do) and not military historians.
Rather contact a Military museum as they would undoubtedly be able to detail each item, its history and also how to preserve these items. Exposure to humidity, light etc can seriously damage such items. Besides, there is no better place then a Military Museum to ensure the history of these items are maintained for future generations and not lost in a basement.
Borden Military Museum: http://ipmslondon.tripod.com/museumreviews/id17.html (Unsure if there is another one closer to Brockville)
Listing of WW2 German Patches: http://www.epier.com/store/outpostflags/Category.asp?cat=3835 Maybe point to the one which most resembles it.