Thanks for the thread -- it encouraged me to look into websites listing senior discounts in Canada, and I found one even I can use! Unfortunately for me (mustachian people problems, I guess), most discounts are for things I barely use any more: hotels and drugstores.
One thing I would recommend: read through *all* the discounts available on websites. A few years back, Hilton had a 10% discount for people over 62, but farther down the list, they had a discount of 20% for anybody belonging to CARP (Canadian AARP) *or over 50*. Guess which one I took?