Stumbled across these fellows making a new router plane:
Well not really entirely new, its a partial copy of the Preston 2500p
with a few features changed, primarily they appear to be only offering one fence and dropped the throat closing device.
The price actually looks somewhat reasonable compared to trying to acquire a Preston as they're going for ~300-500+ depending on condition (they appear to be relatively rare which I'm sure drives the price up).
He has a few entries in his blog talking about the design and why you might want such a thing.
Its kind of interesting, I admit that I haven't felt the lack of features from my old #71 but this design does have some intriguing and I though it was a fun design anyway.