So my mistake...I had Stefan Buda make me a beautiful adaptor all anodised black to fit the Baader ClickLock to the Tak Diagonal...unfortunately I got the thread pitch wrong on the Tak Diagonal side so it doesn't fit (insert face palm here)... Completely my fault... I should have contacted Tak Japan for the correct sizing. The Baader side screws in and out like Teflon (thanks to Stefan...his work is exceptional).
I've since contacted Claude at AEC who kindly contacted Tak Japan for me who confirmed the correct pitch and screw size (M55 at 1mm).
In between I also asked Takahashi America the same question who also confirmed the same size and pitch. After New Year when time allows I'll get Stefan to remake the adaptor for me with the correct dimensions.
I wanted to give credit to everyone who's been involved so far but particularly to Claude at AEC and Takahashi America (Darrin and Fred) who weren't making any money from the project but who offered assistance free of charge. Great customer service goes a long way with me in terms of where I spend my money so thank you to both those businesses.
Thanks also to the many members here who've helped along the way. This is a great community full of valuable knowledge and people willing to share and assist. Thank you everyone.
Thumbs up all round