As previously posted above the dovetails on the OTAs you have will not work on the CGEM. While the optimum solution is certainly to go to Losmandy style dovetails for your OTAs, for these fairly light tubes another solution might be an adapter like the one made by ScopeStuff.
Here is a photo of the ScopeStuff adapter I use on my CGEM, I have found it very adequate for my SW120ED.
Note that the reasonably-priced Scopestuff Losmandy/Vixen adapter can be turned into a side-by-side for small scopes using only an Allen wrench by rotating the in-line saddles 90 degrees in opposite directions, keeping the knobs to the outside. It's solid as a rock, and doesn't add as much mass as some other options. See the photo.
BTW, I love the CGEM. It replaced an HGM200 on a permanent pier, and although the load capacity is lower, the sanity factor is much higher.