Yeah, that's the one (except the Euro pin).
I bought a secondhand Chinook, it's got a bit of slop to it which I think is b/c of the 1.75 washer
You can see the parts here:

These days I get to go to the beach more often but the catch is that I only get an hour in the surf, so I got a Severne Cyclops which has shaved a few minutes of rigging and de-rigging, giving me a little bit more time to play. But when using the Cyclops, the Chinook also feels like it has more slop in the pin-to-mast connection.
I was thinking of getting the old Aeron mast base out and giving it a go, to see if it removes that clicking and sloppiness. If you look at the Severne mast base, besides the coloring, it looks just like the Aeron design.
Maybe I should break out the calipers and see if the pin is a slightly different size.
On another thing Mark, I have finished off the board. Gave it a spray with a can of white car paint that I had lying around, hated it, sanded it back, stuffed it up a little but found another can lying around which matches the board better. Just waiting for a no wind, no wind, no rain, and a bit of motivation to give it another spray. Thank you for all your help.
The Aeron's rope is fraying but other than that it is still in great condition and I just hate to just throw it away.