Probably best to gather specific facts first such as his date of death, birth etc. Then you can try for his forces records. Might confirm your suspicion about being based in Edinburgh around the time you think.
It's surprising in 8 years that you've not been able to find that death.
There's also a birth for a Cyril on SP, different age but again, not too far out to be the same man.
Anyway, I hope that one of them is the correct guy.