Trays...
It's nice to see someone else with an M-1010!Especially with much the same mods i'm going for...time and cash permitting(i blew last months budget getting rid of the DUVAC and installing a new charge controller).
As for battery trays,it's tough to find trays in good condition,especially the rear one.With the old charging system the rear battery would tend to boil over,spilling acid all over the tray and the inner fender.I was able to salvage mine,but had to fab the bracket that hold the battery in place on the tray.
You might try
WWW.steelsoldiers.com
Somebody on this site likely knows your area a little better,and can point you in the right direction