The slats were cut from acrylic safety glass on a table saw, then primed and spray painted. The mesh was bought from a small orders metal supplier. It's 1/4" flattened expanded metal and seems to fit the bill. I cut it with tin snips and thick gloves, as it's steel ad quite sharp. Aluminium or plastic may be a better choice here.

I drilled small holes through each slat and bolted them onto the belt. This was very tedious, but the results are reasonably good, I think.