I had a weird hunch that it might be for whatever reason, but didn't want to spoil the fun...9 out of 10 times its the UK version:/
It sure would be nice to understand why that US verson has such rarity.
Play nice & have fun!!
I second that Muddy the UK one seems to be somewhat easy to find, especially on eBay.uk but the US James is next to impossible, and the ones (3 in total) I have found were from sellers that did not know what they were, 2 of the 3 were in large lots and I spotted the connector from images then inquired to the seller from there.
Would be great to see release numbers on these some time like how many and where they were released, etc...