Sanding and filling Part 17: In quest of a guitar-pick fin finish

In my continuing obsession with sanding and filling so that fins resemble guitar picks, I've tried a new thing that seems to be working out. I'm only done with the first coat and sanding, but it all looks very promising. Here's what I've done:

I've mixed Sig Sanding Sealer and Hobbico HobbyLite Filler in a glass bowl so that the consistency is a little thick, but still easily brushed on. The coat on the fin seems to both fill and adhere better than either one alone. Even after the first coat/sanding I'm getting a really smooth surface already. Admittedly, I'm using basswood instead of balsa. I'm happy to see that the fins don't warp like they have when I've mixed the Hobbico stuff with water.

Has anyone else tried this? What were your results?

I have used Deft semi gloss brushed on and smoothed out with 0000 steel wool. Takes about 3 or 4 coats with steel wooling between coats, and they look like glass when finished and painted.