Yes, I know Golden Green has a 1300w unit. The Rosewill Lightning 1300w is also that unit internally.
I wouldn't say it's a GG unit just based off of that though, as EVGA could have simply requested that SF used higher rated components that allow the Leadex platform to output 1300w.
I attempted to find an image of the 1300 G2 (avoiding images from EVGA in case they had reused the 1000G2 images for certain photos) and just found this video, which it seem like you posted in it. lol
If you look at the back of the PSU beyond the honeycomb grill (pause at 1:20), you will see a coil mounted horizontally, the yellow x-capacitor, a heatsink for the bridge rectifiers and such. It look exactly like the 1000 G2, as shown in your Leadex thread: http://www.overclock.net/t/1390866/super-flower-leadex-information-thread
Where the SF GG 1300w has a different layout: http://www.jonnyguru.com/modules.php?name=NDReviews&op=Story4&reid=240