You don't need to know the wiring of the Honeywell to switch to the FX1. You simply put the compressor wires, fan wires and pump wires on the labeled terminals in the new box. Then you run a cat5 cable to the new thermostat.
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Just wanted to update this thread since I have purchased a NOS Honeywell T6052B and installed it.
I found it on eBay for $97 plus $15 shipping. I liked the price of the first one I found much better ($30 including shipping) but the seller never shipped it or responded to messages. EBay refunded my money with no problem, but being cheap, I would have preferred the $30 total to the $112 total!
Anyway, I no longer am in the market for the thermostat, but don't throw yours out...someone else on the forum is probably going to be looking for one in the near future!
Nick