So getting back to that ugly speaker hole..... I've decided to cut out the speaker hole and replace it with.....another speaker hole.
I couldn't find another speaker with the same bolt pattern otherwise I would have just cut out the two sunken areas and replaced them. But since that didn't happen, that left door open to put in whatever I wanted. I ended up buying a 5x7 dual voice coil speaker. This one is "ultra thin" as I needed clearance to the top of the head unit. This is a Retrosound R-57N.
The plan was to cut a custom speaker grill and graft it into the dash. After a few different designs and test samples, I ended up with this.
I had to keep the metal bars a bit thicker than I wanted as my Plasma cutter isn't built to cut thin material. All it does is burn and melt smaller, more detailed cuts. I had the machine using the smallest (20 amp) tip and turned as low as it would go (20 amps) and it still burned stuff. But it can cut 1.5" if I ever need it too.
I still have some clean up to do, but it's not a big deal. Also, I should have marked the screw holes on the back of the grill before welding on. I didn't, thinking the curve of the dash would throw the holes off, but I wish I would have done it anyhow.
The plan is to try and weld screw "studs" in place instead of drilling holes. I want to keep the dash smooth on top. That'll be next week.