I fly an 172RG and I have the POH. It only shows a decent side view. That will show the landing gear in the down position and where the cutouts are for the wheels when the gear comes up. I have watched the gear come up (retract) from the ground as an RG took off. I have never seen it let down except for the last second or so from the cockpit. My view is blocked. I own a Mooney and I have never seen the gear move as it's hidden from view.

I can describe the gear retraction on the Cessna RG. The legs release and fall almost straight down and slightly back with the wheels almost touching. After a pause they begin to get pulled aft and up into the gear well which is in the fuselage. Upon initial release they do sway with the wind until they are pulled up into the well.

I think it is a two part deal. The lega are on a pivot bar. The legs spread and lock to come down and gravity lets them fall together and down to retract. All the while, the pivot bar that holds the hinged legs rotates to pull the gear back and up or the reverse to go down and forward.

So, for a model, maybe a big pivit bar (like an elevator linkage) would rotate the gear legs back (up) or forward (down). Then you could either spread the gear (down) or pull them together (up) with something. Sounds complicated. But the legs could also just run in a track that did the leg alignment while the pivot bar rotated.

On second thought you might only need the pivot bar. A lock in the gear down position gets released upon retraction, gravity does the work. Wind keeps them pulled backwards and thus wheels together. The pivot bar rotates it all up. The reverse would be the pivot bar rotating the gear forward. Gravity would cause them to spread as the pivot bar (axle) rotated forward naturally spreading the legs into the up locks.

There you go... have fun.