It's not a solution but it's a workaround. What I'm trying to do is to put the scope on the other side! Some local folks have done that and I tried to do it as well, what they were trying to do is to put another scope or camera on the other side of the cub, but in my case, I want the telescope to reside on the other side since it will enable me to reach farther out!
Here's what I've done. First of all, drift a hole on the central of that black disc on the other side of the mount, that is, the engagement knob. It's easy to drill at the center with good accuracy, since it's recessed in the middle. The hole is not very big, around 12mm only and so you will need to decide which mounting screw is to be used. For me, I've chosen 1/4" which is rather like a standard for ball head. While 3/8" would be even better but I found that hole was not quite big enough, remember the screw head has to be small enough as well.
So, I placed a small 1/4" screw inside, it can sit fully within the hole, without hindering the knob to engage the mount.
Put on a ball head... this one is too small and it cannot hold any telescope, not even my now sold Borg 45ED II, so I will need to buy a bigger one soon.
To put the whole thing back to the Cube.
This side of the mount should have less loading, but for my light weighted Ranger at 3.5lb only , it's going to work.
The good thing is that, now I can put my Ranger to the other side of the mount, and it also reaches out more since the ball head is taller than the dovetail saddle! And a great side effect is that, the little cube can hold two telescopes (or one telescope, one camera) now, and it should balance better.
Quite elegant and easy to do.