you can certainly have the motor rebuilt.
labor has gone through the roof, but you might be better going to a motor rebuilder.
i used to get gear motors rebuilt all the time, for a large client, not that long ago, (6-7 yrs) but have recently been told they can't rebuild a motor for less than the price of a new one ($475-$600)
if you expect it to be cheaper than the price of a porter cable router you will be very disappointed, however
you really should bite the bullet and get it rebuilt or buy from gerber, you will have the torque and power of the original as well as the ability to vary your spindle speed.
the sabre is a great machine, you will be very disappointed if you put a junky router in it's place