The seat and cushion are shot on my 345. It is one of the first ones made, in 1995. I see there is an upgrade kit on e-bay http://www.ebay.com/itm/Seat-Upgrade-Fits-John-Deere-325-and-345-Garden-Tractors-Below-70-000-/401198310725?hash=item5d69486545:g:0tsAAOSwNRdX7sxN. My dealer offered a Sun Belt seat that he claimed was the same part, just minus the Deere decal, for about half the price.
Trying to decide between these and looking for a generic seat from Northern Tool, if I can find one that will fit. I thought they look like they would have better suspensions. Has anybody gone with either of these options?