What actually happens inside the six pack has always been a bit of a mystery to me as I've been chasing down leaks and I know I'm not alone; it's a bit of a black box. I emailed HWH a couple weeks back trying to find out and never heard back. Low and behold, as I was sifting through my owner docs looking for Bose stuff, I found this!
I don't think I've seen this shared yet so I uploaded it to the media archives: https://www.foreforums.com/index.php?action=media;sa=item;in=4895
One thing it does confirm for me, if I'm interpreting it correctly, is that leaky pressure switches could cause leak down in the front.
You could, if you wanted to do so, give that page to your local Festo sales man and he could give you a bill of materials for the complete assemble all new. Ask him 'About how much" before you ask him to do all the heavy lifting. Like the guy at the dealership said when I asked for a new S.E.V. Marchal alternator for my SAAB, "Are you sitting down?"
I confirmed this today by pulling one of the pressure switches while there was still a bit of pressure in one corner.
Also, the other pressure switch was fairly loose (actually the 45 degree fitting it screws into) and it was crossed threaded into the fitting. It also happens to be for the corner that leaks down so I'm really hopeful this is the final leak I've been hunting for the front. Famous last words that I've said many times now...