I still use super glue and have always avoided that problem. I paint the inside black, nowadays, so it's really not an issue. However, back in the day, I would only put a couple of dabs on the edges. Not the entire edge.
As for clearing older models, mate... I really don't know. I would paint the outside of the canopy, (whichever colour you're happy with), then varnish over it. Have seen your painting skills, mate. You could easily paint a shine on it to look like the sun reflecting... Be well!