I know this is a long shot, but I thought I would throw it out there. I understand it is very well gooped and maybe not very common. It would be nice with Vox like amps. The original seems quite pricey. I wonder if it is a variation on the Dyna Red, or if a DRD clone could be tuned well for a Vox.
you could try searching freestomp forum you might find something there.
I have already searched freestompboxes.org some time ago. There are schematics and layouts for the DRD, HBOD, SHOD, LGW, and Fire Red Fuzz, but it seems no one has degooped an Emerald Green Distortion.