I bought these second-hand from someone around 1990 or so. I have no idea where they came from, if they were mass-produced, or if they were hand-made by someone – but they’re beautiful! The rails are gold-anodized aluminum (not unusual) and the rollers are varnished laminated hardwood (very unusual!!).
The rollers have a slight taper toward the center, which helps (a little) to keep your wheels centered. They have a heavy varnish, and the wood grain reflects light differently depending on the angle, which makes them kind of sparkle or flash as they turn. I haven’t ridden them for many years, but they’ve been stored in my climate-controlled basement, and the belts still seem to be in good shape.