To make my spacer, I found I needed at least 5/16-3/8" to feel comfortable the belt wouldn't foul on anything. 3/8" was about the max before the footrests would interfere, as well. I tried some aluminum spacers, but they were really awkward to install individually, so I got a strip of 3/8" wide silicone rubber and a 5/16" cutting punch from McMaster and got craftsy, making a spacer that fits most of the way round the perimeter. There's a gap on the bottom/rear for now, but this got me round the block.
[ATTACH=full]74330[/ATTACH]IMG_20191111_093506185 by Mick Doul, on Flickr
[ATTACH=full]74331[/ATTACH]IMG_20191111_093548288 by Mick Doul, on Flickr
Once it was started, I used the punch to shape the inside to help it curve how I wanted from hole to hole. Looks rough from the inside but pretty good from the outside.
[ATTACH=full]74332[/ATTACH]IMG_20191111_100455424 by Mick Doul, on Flickr
[ATTACH=full]74333[/ATTACH]IMG_20191111_100459698 by Mick Doul, on Flickr
[ATTACH=full]74334[/ATTACH]IMG_20191111_150726608 by Mick Doul, on Flickr
[ATTACH=full]74335[/ATTACH]IMG_20191111_150737294 by Mick Doul, on Flickr
[ATTACH=full]74336[/ATTACH]IMG_20191111_162124938 by Mick Doul, on Flickr
