Hi Gordon, he's a merchant navy officer in that one. They wore a generic cap badge or a shipping company cap badge. That one, to me, is a shipping company one. Not clear enough to say anything more on the cap badge, apart from flags were a common design feature, possibly a flag in that one.
The rank piping/braid (two gilt bands and the diamond) on the sleeve is a difficult one as it had coloured trim to identify the branch. He is a; Second officer if no trim, third engineer, if purple trim, or a purser if white trim.
Here are some MN epaulettes on ebay (same design as cuff insignia)
2nd officer
3rd Engineer
[Alan beat me to it!]