I have a Kubota L3710, which was made in the same years as the L4310, but one size smaller, it has been awesome, one of my favorites. Tough, reliable, powerful. Mine is a GST, but you said HST, I would make sure it pulls hills good in M range. The only consistent problem I found, is the front seals have slowly leaked since it was new. ( And dealer repaired 3x, should go again, but it isn't a big problem ) I believe the L4310 has the same axle. These models also had far less electronics, compared to current models. If it is in good shape, I would buy it and not think twice.