From what I've seen in others photos, the compound appears to be between the workshop area and the work train sidings, so not publicly accessible, or photograph-able without entering the site.Its hard to access. I did see the siding on the last Heritage Express tours which went via the chullora and enfield freight sidings.
There seems to be at least 3 to 6 8 car sets near the scrapping machine. There also appears to be a siding at port enfield where I saw at least 10+ 8 car S sets. Its seems that that siding does have overhead power but all the panto's seemed to be down. I did try to take pictures but was on the wrong side and my photo's weren't coming out (also had issues with my phone's camera at the time).