Well, since a 512k Mac isn't the most useful of beasts anymore, you're probably best to go the collector route - several of them have sold on eBay for $24.99 in the past month or so.
You could likewise try the IIci on eBay - while there is no guarantee it will sell at all, again it's main appeal is going to be to collectors. One sold recently for $25, but another one at $9.99 didn't sell. Unless you know someone with a young (ie: too young to know about any current games!) child who might want it to keep 'em occupied and off Mom & Dad's computer, there probably aren't going to be many takers.
Failing all that, you can drop things off at Goodwill in Boston for a fee (can't remember exactly, but I think it's $5/item) and the Salvation Army in Saugus (Rt. 1) and there are a number of resources listed here:
http://www.state.ma.us/dep/recycle/crt/CRTRSBZ.htmhttp://www.state.ma.us/dep/recycle/crt/crthome.htmThere are places on the lists that take computers for distribution to various needy organizations/people, but I doubt that any of them would be particularly interested in either a Mac 512k or a IIci.
Electronicycle, on the list in the first link takes stuff for recycling, but it's a bit of a trek, since it's in Spencer (past Worcester) on Route 9. Don't know if they charge or not - you'd have to call them.
And of course, there's always the disassemble route. I've done that! My kids think it's great fun - especially extracting the rather powerful magnets in hard drives. This is not recommended with CRT's though, and you should still make sure that you drop off anything potentially toxic to a facility that recycles. My husband has a massive (and at times quite useful) collection of carefully sorted innards (capacitors, resistors etc.), but most people aren't quite that crazy.
