Looks like these guys have something close, but it uses corner holes instead of centred ones.
Mojotone 4-Hole Mount Soapbar Bass Pickup Cover Black (Small)
I checked, even GJ's distributor is clearing out their inventory it looks like. Other than that, Dave from Frets on the Net can make you some rings that mount internally, so you don't have to put any holes in the top of the guitar
Ebay might have something, too.