I may not be as fussy as most, but mostly approach this whole vintage thing from a pragmatic 'utility-first-let's-ride-instead' attitude.
I reuse old bar wraps, finish off with electrical tape plus other cheapskate tricks, and I find shellac fitting marvelously into that scheme. It rejuvenates crappy tape, can be reapplied on a whim any time down the road without surface prep and is ride-ready in minutes here on the dry side of the continent. I even put a few coats on some really bad looking white Campy brake hoods, which arguably gave them a new round on my wife's bike.

I only use the dry amber flakes and keep a small amount of mixed shellac in a peanutbutter jar with a chopped off 1" brush inside, ready for immidiate use on large and small jobs. If it dries out (alcohol evaporates quickly) just mix it up again. It typically takes a good day for fresh shellac flakes to completely dissolve into a useable liquid.

The best thing about shellac is the 'you're kidding' look one gets when elaborating on the beetle poop origins of the flakes!