Paul was right..
Just had a closer look at That main foam seat..
The plastic base is from the very same mold and the foam over molding has been done is a tool with identical numbers (overmolding foam has replicated the number in the foam material as well ) ..
The foam mold cavity finish is a bit rough.. maybe a sample run only ?
Seat is a 20 mm shorter than the SP4/5 version seat on the front side making the flip tank move a bit easier when opening up..
