Here's what I did, I copied the _MODS folder, JSGME.exe and the JSGME.ini over to the new folder. You have to edit the .ini file in the 1.2.7 version to show the directory path that it now resides in 1.2.7. If you don't, it will move the mod files in 1.2.6.
I also renamed my JSGME.exe's to JSGME_126.exe & JSGME_127.exe, etc. This way you can run a separate instance of this app for each instance of DCS you have.
Let me know if you have any more questions.
You'll need to extensively test each mod too. As Skate said, it's not recommended. Reason being, some folder structures may be different on 1.2.7 vs. 1.2.6. Use mods at your own risk.