Presume you have used paint stripper to get this far so either put some more on and let it do its job or we normally plastic ead blast frames for the raw look as the plasic bead does not effect the ally or bb threads. Wouldnt bother lacquering it as it never sticks to base ally very well unless is keyed up by scuffing the ally with scotchbrite pad.
But you do need to keep the air away from the ally as it will quickly oxidise and pick up road salts so a oily rag over it regularly or we tend to use car wax .
Or you could have it clear powder coated but thats a bit of a lottery so you need to have one recomended to you to avoid a mess.