Could this be it?
Shiro Kashi Saya Bokuto
This is our shiro kashi bokuto (without hi), with a plastic saya and our leather single layer tsuba. The perfect beginning step for iaido students, no more pretend saya or trying to hook your hakama himo to get the bokuto tucked away at the side.
More importantly, you can practice noto correctly, with the left hand at the centre rather than at the left hip.
If there was something, some kind of grip actually ON the handle, I'd have to say he or the person who sold it to him added it on there. /shrug
Goodluck with the hunt! I'm pretty sure if there was another out there with a saya, I'd know about it. This is the only one that comes to mind... via the internet (aside from one at e-bogu mentioned above).