Something like
this, maybe?
Meanwhile, a glance at a few websites appears to indicate that Caradyne stuff is generally available in the States. So I'm wondering if one of the UK suppliers can help out (by shipping some across). The trouble is, of course (and as you have already found), that the dollar price simply becomes the price in pounds (or worse).
As I say, "if it were me" I guess I would go for an "engineering" (read as "cheaper") solution; and also one that is sustainable in the medium to long term. Why do I say that? Because I despise the
gougers of the world. LOL.
But (as already mentioned) I reckon that EnviteC is the top quality option. Made in Germany, I believe.

Meanwhile,
here is some information from Teledyne (with yet another cross-reference
.pdf). And (lastly)
here is another source a little closer to home.
But not the sensor you are looking for, unfortunately. I wonder who the OEM is for that one?
