Whoa, that's oddly specific and also kinda gross at the same time. I mean, attics usually smell like dust and mothballs (and maybe a dead mouse or two), so grandma must have had some weird hobbies. Did she also collect old paint cans and varnish for fun, or was she just really into refinishing furniture on the weekends? Either way, that's a memory that'll stick with you forever, probably longer than the actual shellac smell itself. Not exactly the kind of nostalgia you can buy at the store, you know.