After a trip to the hardware store, I have been working in the shop this week after the kids go to bed. I'll post photos later, but it seems as though I have a much better result. I'm putting the finishing layers of paint on it now, and waiting on drying and all that.
I ended up just making a few "corners only" pieces. I have to say that in the early stages, the difference is quite noticeable. I'm pretty pumped. I got a finer filler, but next time I'm in town, I'm getting some Bondo to play with as well. I'm also playing around with base coats, primers, sanding sealer, etc...
There are a few tools that need to be upgraded, beginning with my miter saw! It's 45 degrees isn't exactly mathematically true, so that took a bit of adjustment to find. I also like the recommendation of a new, smaller, blade.
Maybe I can make a decent enough frame or two to sell, then treat myself to a new saw! That's the plan, at least. My husband says that the shop has to now pay for itself. :)