My guess is that you don't really want to re-paint the baits. Also, I imagine that if there are age cracks, that the paint is lifting in these areas. If it were me, I would sand the old finish off, re-prime/re-seal, paint and than top coat with an epoxy.
You could use some nail polish (which I think is just laquer), or you could use laquer, epoxy, urethane, etc., but I think you will not be happy with the results.