That won't fit either :/. What is that mount?
oh and dont get too hung up about where the centre hole it either, as its offset on a stock SR rear mount and central on the poly.
Prothane.
Just remove the rear mount from your grey one and send it to Tegiwa they can fill it with whatever hardness poly urethane you want
Just so long as they dont sell it to someone else after you've paid.