I've uploaded a picture, where I had my scope assembled to test if I can balance it. From an imaging point of view this setup is a bit nonsense but I did that because the focuser is quite heavy and also I prepared to go into the mono shooting with filter wheel. The DSLR served just as a weight substitute for the mono camera which hadn't arrived by then. Also the placement of the reducer (it was with the Meade) is wrong. It would be after the focuser. Nevertheless, you might get an impression about the focuser's size. With all that stuff attached, the tube gets quite long. I'm not using an OAG mainly for the balancing purpose and tried it with the guide scope on top.
One more thing:
I've now determined the effective focal lengths. When I shot with the Meade attached directly to the tube (without Crayford), the reduction is about the 0,63 it's supposed to have.
Now with the Crayford and the AP reducer at the end, I'm not getting the nominal 0,67 but only 0,8. The effect comes from the Crayford since I need to change the FL of the SCT significantly to bring the focus point quite behind the tube. So instead of having 1300mm, I was shooting with 1600mm FL, making an f/8 out of my f/10.
Nevertheless, I'm quite happy with the resulting image quality: https://astrob.in/rwezw6/C/
The image is cropped to emphasize the open cluster and due to some offset between the LRGB channels.
Tomorrow should be a good night and maybe I'll go for M1. Then I'll use the SCT and try another back focus to make the scope faster. I could make a photo of that setup and place it here as well.