Can't remember if that hood is plastic or fiberglass. Is the glue from decals that have been removed? I tried lacquer thinner on a plastic 74 T'NT hood - bad idea, started removing the plastic as well.
I use Sticker-Off for removing trail sticker adhesive but don't think it's strong enough for factory decal glue. You could try the stuff from 3M for removing auto decals. I've used it for removing graphics on my vintage Polaris tunnels but it's pretty agressive. Not sure if it is safe for fiberglass/plastic.
As far as restoring the shine, don't really have any unique suggestions other than the obvious (buffing etc.). I guess worst case you could clear coat it.