My brother's mechanic is supposedly reliable, so I'm hoping he's thorough. I don't believe he'll rip me off or do bad work. Thanks for the info about the valves.
I run techron or Lucas fuel system cleaners frequently and no changes to the gauge. It reads empty in about 200 miles, and I get 350+ on a full tank. next time I'm empty I'll try cleaning the sending unit relays. The speedo and trip meter seem to work fine. My haynes manual indicates a sending unit with the pump (passenger side access) as well as driver side access. Cleaning before attempting to replace is good advice, and frugal.
So I'll check the clutch switch, brake switch, then look for dreaded vacuum leaks.
Thanks for the advice, please keep it coming. Can anyone recommend a good short-throw shifter or mod?