OK, I heard back overnight from my contact at Starmix as well as several of the many retailers I contacted.
In regards to Starmix, there is no chance of any of us getting ahold of even a prototype of the forthcoming OEM sys-dock. I offered us up as a test group but they didn't bite. The two part numbers (for the lid and the rails) were confirmed as being correct though I'm not sure why this confirmation was offered as I didn't ask for it. There was also no response to my question about whether Starmix could supply us directly with the spare parts (as opposed to us having to track down a willing retailer). I will follow up on that (again). My contact also warned me that installing these spare parts would be "at my risk" and that doing so would void the warranty.
All but one of the retailers who responded were sorry to say that they couldn't get these parts. The one that did respond, though, forwarded a quote that produced an automatic sitting response. Get this, including economy shipping, for each of the lid and rails combinations, they want £190 (or US$248.71 at today's exchange rate). That's £95 for the parts and £95 for the shipping. After that, the math breaks down a bit. If we want to ship two full sets together at the same time the total price increases to £420 (US$550.03 or US$275/each). This isn't even close to what the parts sell for elsewhere.
I don't know about anyone else but for me this offer is a total non-starter.
That being said, I've personally found that shipping costs from the U.K. is often so out of whack with other locales (like Germany, the Netherlands and France, for instance) that I still have some hope that I can locate a more reasonable offer. It may even make sense to group the rails together as one shipment and then ship the lids separately - the latter's size is a big part of the problem. That said, if they nest together (not sure if they do) I can't understand why the cost would be so obscene (even knowing what I know about U.K. shipping costs). So, stand by on that front too.
Other than that, I'm of course open to any ideas for other workarounds. As it currently stands, I might be installing that Karcher sys-dock after all.
