I'd checked with ICAS and their response wasn't satisfactory. I doubt they recognize SCDL diploma. Heartbreaking??
I later checked with IQAS and in their email response they confirmed that they will assess SCDL diploma. They sent one document also (can be downloaded from their website as well), and SCDL was listed. So, my most educated guess is that SCDL diploma is considered by IQAS and you should approach them for ECA.
SCDL TRANSCRIPTS?? Make a note of your registration number and call them. Their customer care number is given on SCDL website. If you want, please share your email I'd and I will forward their email response with complete instructions.
Hop this helps...