I'm wondering about the durability of the trim. I know you garage "LT" and the trim might last quite a long time. And, it looks like it could easily be replaced.
However, if you were to go with something more permanent I see the options as:
1. Tinted epoxy inlay. This would create a flush surface. Template route a shallow recess (avoiding the screw heads), fill in with epoxy and then sand flush. You'd probably need to use an additive filler, creating a leak-proof containment dam on a vertical surface when using "plain" epoxy mix would be challenging at best. Or, just get a group of friends to tip it and hold it while you work.

2. Wood epoxied to surface. Same design elements, maybe in black?
Great score on the lamp!