The GP dovetail is undoubtedly the de facto standard for small to medium sized mount.
Yesterday night, I realized that its dimension is not far from another de facto standard for the quick release plate of many generic photographic ball head.
This kind of quick release plate comes in many different length, and more importantly, they're far cheaper!
I've ordered two therefore, to be used with my Ranger and even other camera lens.
Both my Nexstar SE mount and my GOTO Mark-X are using similar dovetail saddle!