I just had to take a little more material out of the dowel and screw holes to make everything fit easily by hand; didn't want it to become a struggle with the relatively fragile piece down the road and possibly bend something, plus I cleaned up the sharp edges left by machining.
I also opened up the hole in the backplate where the wires pass through a little more, and also flap-wheeled that to super-smooth. The way the cutout is designed, I no longer have to fish wires and connectors out through that stupid hole...it's open to the top when the cutout is removed, and trapped in place in the little cavity I left once I put everything back in place.
Drilled some little drain holes in the bottom of the spacer, too, since it's not weather-tight.
Lastly, I need to take threads off the forward chaincase plug so that they don't interfere with the belt. Gonna mark the position it's in when it's tight and just grind away what little is needed for clearance.
So I'm here now, and it's exciting!
[ATTACH=full]74511[/ATTACH]IMG_20191205_121309081_HDR by Mick Doul, on Flickr