No opinion on the SS-1, never used those. But if you really like the Fender 57/62s, you can DIY a RWRP middle. You will need a compass (a cheap toy one will suffice) and a fairly powerful neodymium magnet. There are tutorials on the web showing how to do this, basically you find whether the coil is north or south with the compass, then find the opposite pole for the magnet, and apply the magnet to each pole piece (opposites attract and all that) for a few seconds, then double-check with the compass that the magnet has been repolarized.
Then you simply reverse the wiring of the middle pickup, this takes care of the "RW" part of the equation.
Just remember to keep that magnet away from the other pickups, other guitars, or any hard drives, USB drives, etc. Since you have to reverse the wiring anyway, it's probably safer to disconnect the middle pickup and remove it from the guitar prior to remagnetizing the pole pieces.