I found some information on Okinawan swords. As kobudoka seem to use whatever ‘sword’ they can get a hold of as a rochin, it may be more appropriate to use Okinawan/Ryukyu swords. Okinawas seemed to get many blades from Japan.
This is a long Ryukyu sword. The blade is Japanese but the handle is definitely intended for one handed use. It may be a big too big to use as a rochin.
This is a short Ryukyu sword. Again, maybe a little too long for a rochin. This is basically a wakizashi.
This is a knife with tanto style fittings.
The info cam from here: https://markussesko.com/2014/09/01/r...rade-loophole/