Here's Dave Mates: https://alba-valb.org/volunteers/dave-mates/.
I'll see if he's profiled on the Geni tree and will list him if not. (just done.)
Very small bit about Helen North on ALBA-VALB, nothing on husband Joe.
If anyone would like to send me information on relatives who volunteered, I'd be happy to include them i the Lincoln Brigade project on Geni.com.