Hi Doug. Definitely can save weight going to solid state/digital avionics stuff. I am looking into a full panel replacement and expect to save 10, maybe 15 pounds (=/-, depending on how much removed, includes of course removing the vacuum pump mess). People who’ve actually done this can give an actual account. I have the old BN autopilot vacuum servos and gobs of other old wiring still installed so will benefit by getting that out as well.
As for fuel procedures, it takes conscious awareness, but not an inhuman thing. Many planes have similar 4 tank, single selector, low wing situations. Problem with us is only one gauge, on the active tank. By installing a 4 tank fuel gauge system most issues are gone. For planning, right after takeoff upon passing a safe altitude for return to airport I will switch to an outboard tank. You should plan to use those up first. Assuming full fuel, I would run at least 1/2 hour then switch. The ailerons and trim can handle 5-10 gal 30-60 pound weight/bal issue, so sometimes I go an hour. Just keep track of the time/fuel used on your kneeboard and there’ll be no issues for the next flight. Or better yet, just get a Shadin or EI fuel management system to help keep track.
Hope this helps, we do love these planes …rarely sell them. There are a lot of older owners, so now is probably the big opportunity to get into one!