The only hard part to the idea is being able to secure the brass extension (for the angle cock) to something else on the car. My first two test cars were easy since one had a brass underframe and the other had a very thick bolster that I drilled out to fit the extension. The brass extension piece was made from .046" diameter brass rod, which allowed me to solder the PSC angle cock easily.
For the air hoses, I followed the OST article for the parts, which work great. The only step from the article that I felt was not possible was using a 3/32" bit to drill into the glad hand further. The bit kept getting caught on another part of the glad hand. I just made sure the magnet would fit into the underside of it and glued it in.
As for deciding upon an air hose length, which was not mentioned in the article, I feel that 1/2" is long enough to look about right and still connect the glad hands together, even if the magnets are the same polarity facing each other. That was a possible issue when using these, but they still connect close enough for it not to matter.
As for the resin car with the thick bolster, I used a #52 bit to drill most of the hole from the car end side, but then I finished the last part of it with a #55. This provides a very snug hole for the .046" rod that needed pliers to push the rod through. Once through, I bent the wire on either side to try to provide an extra step to keep it in place. Paint can be added afterwards.
Here are some photos below: