for the IC locked motherboards, try doing an anti-recovery flash with 3uTools, then use 3uTools to try and activate it (or try activation manually). if it's still IC locked, then it's ebay fodder. people do buy IC locked motherboards for component parts or for practice. some have some "magic" way to remove IC locks (or so they say, just don't buy any of their "services"). as the saying goes "one man's trash is another man's treasure". if you can bundle the mobo, home button and SIM card together, it's a little more attractive. they won't get big bucks, but they will get you some money.
regarding everything else, save them for repair jobs. sure they're used parts, but if they're working well (you've tested them, of course) they're sometimes more desirable for customers because they're original apple products. in many cases, 3rd party OEM grade components are just as good as the real thing, but many swear by, and must have, that apple logo on their replacement parts. especially when you save them big $$ because you're using apple parts, but not charging apple store prices.
if you have a surplus of a particular part, or you've decided not to service certain models of phones, you can definitely sell those parts on ebay as well.