I use a 1 meter Winegard now,but did have a 76 cm Winegard on an
SG2100 for a year or so. I didn't have any problem mounting the dish to that, I think the motor you have and the sg2100 are identical from what I've read. I still have the dish and a spare sg2100, if you like I could send some close-up pics of the dish mount, declination scale with motor mounted, to give you an idea of how it should look. It might give an idea of what is different about your setup and how you might go about fixing it. :mozilla_sealed:
Have you asked the place where you bought the setup why it won't go together properly?
PM me your e-mail if you want to have a look at the pics