architect,
I'm supportive of your quest to get the seatbelt issue resolved. In the normal "drive the tractor" mode, the belt is pretty short. Works fine for skinny guys, but really needs to be longer for many folks. The second issue is how it works in backhoe mode, seat spun rearward. In that case, it is located in the wrong location and does not work at all. But as I have thought about this, it has come to my attention that most backhoe attachments have no seatbelt. On all of the backhoe attachments I see with their own seat (a second seat) like our 3720, 509/511, 485/595, 2710/3710, 1710, etc...none of them come with a seatbelt. Is a seatbelt needed or required on a backhoe attachment? I just don't know the answer to that. Our Max tractors have seatbelts that work when the seat is spun, none of the rest of the Mahindra like has such a feature.
Just some thoughts. Not trying to open up a can of worms, but I do find it interesting that backhoe attachments generally do not have seatbelts. I'm not sure how that is in other brands.