The cable arrived after 3 days but did not work.
The SCART connector end had pins 19, 17, 15 & 13 connected to white, blue, yellow and pink wires respectively. Most websites suggest this is incorrect, but I have so far been able to find the correct combination
UPDATE:
I contacted CDL Micro on their support line. They were really helpful and promptly sent a pdf diagram of their wiring to compare to this:
[...]
It turned out the left and rights are mixed up for the s-video.
I swapped pins 19 & 15 and 17 & 13 at the SCART end which got it working (you can do this with some fine tweezers, no soldering required). CDL Micro initially thought the diagrams suggested it was correct and were going to offer a freepost refund or to send our a replacement under the assumption it was faulty.
Since it now works, considering its price I've upped my rating to 3 stars.