Slight misgivings began when an order confirmation showed an additional EU 2-pin to UK 3-pin snap-on adapter (of the type suitable for shaver style 2-pin leads, not wall-warts). But snug in my belief that the box would contain all 4 AC pin adapters, I put aside any fears and awaited its arrival.
It's just arrived. But with only an EU 2-pin AC connector to snap into the PSU and a totally inappropriate 2- to 3-pin adapter that absolutely won't work with the PSU. Even if the hole in the side of the adapter was big enough to fit the PSU pin base through, it wouldn't grab the PSU and would be totally unsafe.

Before contacting Thomann, I emailed Drawmer to see if they supplied Thomann with all four AC-pin types, or just the EU one. I got a very prompt reply from John Lamb of Drawmer, saying that whilst they did initially supply all 4 adapters, it was costly to do so, and three always went to waste, so they no longer did so.
However, Thomann chose not to keep a stock of the UK converters to be supplied with UK orders, but instead send out these absolutely useless converters (which I believe is against EU law).
But Drawmer are now sending me the correct UK adapter plate free of charge, so a big hurrah! for Drawmer and a big boooo! for Thomann, whom I will now never use again. Drawmer are also going to update their manual to reflect this.
:SOS: - It's probably worth updating the web CMC2 review with the fact that only one adapter plate is now shipped with the PSU, so always buy from the country you plan to use it in.