Resolved own issue by running through CKAN with -force-opengl command line parameter. Belts render and appear correctly. Then removed -force-opengl and belts stopped rendering. Tried running on 32 bit KSP without -force-opengl and get message that belt was rendering, but belt never rendered.
The issue seems to be directX rendering on an Nvidia 9XX, regardless of other mods or KSP 64/32 bit.