I'm sorry to hear about your dad. I'm sure you'll find a good home for all his equipment, among the users on this site.
I know you've mentioned photos, but as an extra thought, it might be nice just to print some out for your dad, I know sometimes that's what I do for myself (and I'm not even nearing dementia, yet!), but I like to look at pictures of my old cars, old computers, etc. Brings back a lot of memories...
