Thank you all for your good advice. You are wonderful!
Special thanks to BartS -- you actually helped me take a deep breath and decide my next steps.
Here's what I'm going to do:1. Using Bart's suggestion, I will go through each system (he has 6, plus miscellaneous stuff) and get it all spreadsheeted, doing one system a day over the course of a week or so.2. Locate the boxes (yes, hoarded those, too) and paperwork/manuals and match them up.3. Get everything dusted and take photos.4. Let you all know when I've done that and where you can locate the sheet and photos to look at. (Will park on my website on a hidden page.)5. Then see where things go.
While I'd like it all gone tomorrow, I really do want to get back some of the value, as I've worked years paying it all off as he went along. (Note to those of you with a non-stereo spouse/significant other!) I figured if I floated the problem of getting rid of it all to you guys, you'd have good ideas. Thanks so much, and I'll be back with more details soon.
Becca