Michigan Iron & Equipment built the mech. thumb I put on the BT820 that's on the B26TLB. It was a pin on using the existing thumb bracket (I think the BH92 has one as well?) Thumb was beefy, very well built, and a perfect fit, the one issue I had was the new shared wrist pin was too short. They quickly responded with a new pin and covered all shipping. Not sure they still build Kubota thumbs as their web site pushes Kioti but worth checking out. MIE LLC
/ Want to buy mechanical thumb for a BH 92 kubota backhoe