In avoidance of paying over $500 for seats that fit the 17.5″ allowable seat width that the 442E chassis demands,  we picked up some old Honda Prelude seats as a starting point. They were a little wide,  but were stripped down cut in half and welded back together. Before work could progress further,  reasonably priced seats came up online locally that fit with a little squeeze nicely into the chassis.  Have yet to work in some sort of rail slider to the bottoms yet.