The family could start out with a comprehensive Refurbishment verses a full-blown Restoration. But if their wishes are for it to look like it did when purchased and are willing to finance that wish, I see nothing wrong with that as long as the job is done right.
1 vote here for leave it be
it's a very cool bike and it'll never be more interesting than it is now.
clean it up or "restore" it, either way it'll be sanitized, the history and character wiped clean, lost forever.
If this bike was purchased at an estate sale or a bike swap, I'd say restore it. The fact is the bike is already wearing the family history, complete with the recovered seat, mismatched screws holding the tank together and even the wire securing the brake arm. I'd be hard pressed to touch a thing on this bike. It's an heirloom as it sits! Of course, this is just my opinion.
Completely disassemble, wash all painted parts. Soak chrome in evaporust for 2-12 hours, use polishing compound on painted parts very carefully staying away from pinstripes. Also I used some 0000 steel wool and wd40 on some of the paint, keeping away from stripes still. Then washed again and waxed w carnuba
That said, I don't have much hope for the original rims. They are deeply blistered with rust. I am thinking I would like to build new wheels around the original hubs. Any tips on finding similar age-appropriate hoops in better condition? Also would like to replace the tires, which obviously are not original. Owner says he remembers them being white walls.