Jeremy, the end of the focuser tube on the 3 larger Esprit models (100, 120, 150) is M74x1 as I understand it.
You might be able to find someone who will make a custom adapter to meet one of the ClickLock adapters - which one were you thinking of?
I have the 2" ClickLock diagonal and the front nosepiece unscrews for use on the smaller SCTs directly
