Cool idea Bob. I have used super glue (CA) as a seam filler on plastic models for years. In-fact it can be sanded so smooth as to look like glass. I have even used it to create glass lenses for wing tip lights on aircraft. But you cannot allow the CA to cure overnight as it will become too hard to sand... sanding needs to start just a few minutes after the glue has set. In this way, it remains somewhat soft (believe it or not). Another trick is, after squirting the CA into to the seam, dusting the glue with a coating of baking soda. This will create a chemical reaction that will instantly cure the glue and keep it soft enough for sanding.I decided to try an idea I had.
Super glue (CA) is a magical thing but takes some experimenting to figure out all the intricacies for use.