Thanks for the good info. I've read that (in CA) even if there is no probate, a will must be "deposited" with the Superior Court. I didn't know about the DMV, but the car (I hope is titled to the trust) is at least in joint tenancy w/surviving MIL from one old copy of the pink slip I've found so far. Need to look at current registration. Found an old grant deed on the house and it, too, is joint tenancy, and hope to goodness they re-titled it to the trust. I think I saw a packet with another grant deed on the first pass through the files. Have to go back and find out what's what. We have the estate attorney who wrote the trust and will probably call once I find out as much as I can so I can keep it brief with him.
We are dealing with the things that need most immediate attention first, obviously. Have handled Social Security, and are awaiting a packet of forms from the insurance company that has the company pension. Will contact the life insurers in the next few days. Fortunately, FIL was pretty together on record keeping. Still it is quite a bit of work.
Personally, I've got everything organized in a folder at home with a copy in a safe location with all info including addresses, phone numbers, account numbers, contact names, etc. so it should be less problematic for whomever get the chore.