So some EMU info
When you say "cage" I'm not sure to what you are referring. There is a shoulder style, developed by Litton for the extended Apollo missions, called a rolling convolute, which was further developed on the Mark II suit. Is this what you are calling a cage?
There were two styles of EMU HUT, one with an articulated bearing at the shoulder (single plane) and another without the articulation, with just a fixed bearing. There is a FRP HUT on Orbital Surplus right now that was made using a real hard upper torso plug.
As far at helmet disconnects with 8 retracting pins.
These are pretty complex, requiring about 35 precisely machined parts in stainless steel and aluminum. The aluminum must be anodized, otherwise the aluminum is to "waxy/ sticky" to make things move smoothly.
In the near future, I will be offering some Gemini / S-1030 beringed helmet disconnects that are nearly identical to the real ones (only missing internal seals) with a16 pin engagement, they will be in the $3500 price range. But these are an 1" smaller in diameter than the EMU rings and do not have the proper HUT mounting surface arrangement.
Here is the ring without anodizing. (Gemini would be light blue and the S-1030 is Class 1 anodizing, which is a mottled light grey with a black release)
View attachment 1796300
A less expensive alternative is ball detents or spring plungers.
As far as material, we have not found a substitute for the Ortho fabric that looks close. Most replica suits just use a Nylon or pack cloth fabric, which we use on our lower grade suit replicas, as Ortho fabric is not being made, unless custom ordered, and if some is available it's $450/yrd.
Yes, it is LMGILL