Looking for a standard oval toilet seat with a not so standard hinge? Take a look at the RTS 240 mm Wide Hinge Oval Toilet Seat. It's a Duroplast seat with slow closing seat and lid:
These seats are sold with adjustable hinges to accommodate a comfortable 240mm width when measuring from the centres of the pan holes.
240mm Wide Hinge - Duroplast - Oval - Slow Close - Adj Hinges - 1 Button Quick Release - Sorted!