Mamiya RZ-lens cable-release-mechanisme

Dont have mamiya RZ yet but 180mm lens. When trying out the aperture mechanisme successfully today all of a sudden i had two parts in my hand. tube and lens-part.
later i have found a 24x9x5mm approx. copper omega-shaped blade with hole on the carpet.
1a) dont know where it must sit.
2. then i tried to find out how to have access to the screws for reattaching the main two parts.
found it out but dont want to go into details. need not remove screws.
3. then when trying or finding out how cable-release-mechanisme is working all of a sudden the pin(small tube open only on one side) went off inside.
Now the mechanisme i could easily remove from outside.
3a)
But how is this pin fixed inside.

no chance to reposition only to find out it will fall off again. Thanks

1. unknown coper-item from inside rz67-180mm. 24mm lenght together with cable-release-tube(pin)
2. cable-release pin(tube) open on one side.
3. situation inside tube with big hole for cable-release-tube
4. cable-release-tube with pin
questions:
1. where to put that copper-omega-shaped part? maybe between hole and wall holding by the two elements(lens and tube)
2. how is cable-releas pin attached so it cannot go off? maybe only when lens is closed.
so remains question 1.
thanks
nb: i didnt open the lens. the parts came off. maybe i did force the mount-ring too much.

Why all this fuss? When i manipulated the lens-yes i know where to trigger to make the aperture work- all of a sudden i had two tubes in my hands.
after succesfully triggering apertures(with a certain combinaton i could not stop down completely) i could neigher attach nor release lens-cap. in the meantime i also wanted to know what function has cable-release when camera is absent..... the all of a sudden when if force- turned the mount-ring i had two tubes in my hands. and most probably that copper-omega-shaped part fell down.
i have found a parts and repair-manual. will consult that later. or if someone can help.
I think the mechanisme how the tubes are joined is not the best i would have chosen. they added slits instead of holes to be able leaving the screws on the other lens-tube.they are accessible trough holes in the tube. one could imagine what will happen when the are losening.

Have found that part in parts list. photobooksonline dot com or on ebay -one must take care of screw M5122-S4411 which is showing a tiny roundshaped item under the screw. thats a white plastic ball. not mentioned seperately wierd. maybe its a combo: screw plus ball.
reconstruction should be easy.
interesting is the infinity-adjustment with shim. when i have rz-35mm-adapter i could check that digitally.
Is there a cheaper alternative to the fotodiox-solution? maybe only DIY.
RZ camera service manual on cd is on ebay. most certainly only body.