The 4th gear lockout switch I have seen are one wire. Looks like a bullet connector. It sticks out of the RH side of the top cover. The switch for the rear backup lights is on the other (LH) side, two wires.
It is possible to repair the wiring, I would say necessary in your case. As you say, access is more constricted in the 2xx series so you may want to drop the rear of the trans as low as possible.
Sorry I don't know anything about bypassing the solenoid or relay, no idea on how that would even work or reasons why.
LATER EDIT: Maybe you're talking about modifying the earlier sliding switch type of OD control?