" I came up with a fairly simple idea using hydraulics with brake
master cylinders to supply pressure. Problem is the wheel will either
still steer when retracted making for a big wheel well or any disconnect
system I can think of becomes complex beyond my pay grade.

I had considered cables but every sketch or model I can think of tends
to put a lot off stress on the cables or downloads tension when retracted
depending on which side of the pivot point the pulleys are. This makes for
some interesting spring configurations. If anyone has solved that I'd like
to hear what solution was derived.

Tension the cables correctly when gear is in the down position, and have the
pulley at the pivot point arranged so some slack develops when gear is up.
Keep the cable under slight tension while up, so it does not jump a pulley
and so cables will not move the gear while up. That could be achieved by
putting a pulley around the cable in a long run attached to a light spring
going at a right angle to the cable run. That would keep things snug but
allow movement.
--
Jim in NC