Cellulose certainly would not suit the base colour enamel paint unless you need to strip it.

I found an acrylic lacquer in spray but that came out a bit cloudy looking.

Jamie,
You don't state what type of paint you've used first.
From bitter experience, I'd advise care and caution about using spray lacquer (varnish). I used one claimed to be suitable over enamel paint. After about 1 month, the clear lacquer 'crazed' on all areas irrespective of whether there was heat below or not. Removing the dried lacquer necessitated reapplication of the enamel followed by use of a brushing varnish which used white spirit as its solvent. After that all was well altho' there was some yellowing of the brushed-on varnish.
As so often advised – try any sprayed paint, lacquer etc over an inconspicuous part first and wait some while to check for a reaction.

IMHO, based on a lot of reading, most new 'passenger' locos were outshopped with a many coats of gloss varnish. But Chistopher Vine's book is probably the definitve source for methodology in our scales.