I haven't built in a while and looking through some old stock. At some point I had bought 2 SAD1024 as working on ebay but never had a way to test them. I also have a broken mxr stereo chorus pedal with a SAD512 in it. I'd like to get some value from these. How can I get them tested and is it necessary?
You could try to find someone who has an old Morely PFL Flanger. Those had the SAD1024 in a socket, so yours could be swapped in easily to test them out. With the prices SAD1024's command, I'm sure nobody would take a risk unless they were proven to work.
You could build this
https://www.oakleysound.com/Vintage_Flanger.htm
Alternatively, I could help you out. I have built one of those and I own many vintage EH pedals with the 1024 in them. Shoot me a PM if you'd like.