Welcome, a lot of people have dealt with those issues of window repairs and
painting. Lot of different approaches and types of paints used. In a little while you will have several different options offered I'm sure.
All paint will chip when hit by road gravel etc. but I have to ask why do you want to paint a
scamp? Did you have body work done so it needs to be painted? Or a desire to have a color scheme of some sort?
If you are dealing with an old scamp that just has no shine you should read this post and check out the pictures. You can clean these old eggs and apply an inexpensive floor wax, yes floor wax and get a like new shine. And scamp still sells all the original decals.
http://www.fiberglassrv.com/forums/f56/check-this-out-not-poliglow-time-will-tell-43004.html
My 77 scamp could almost pass for a new trailer after I gave it a good cleaning following the advice sprinkled in that thread replaced the decals and applied Red Max. My first trip out I got a "no way" when I told a fellow camper the trailer age.
I would add that a picture of the window might help folks respond, scamp changed
windows from time to time and someone may have repaired the same
windows on a different year and not know they are also on an 84