Ah, I was out sailing a few weeks ago in the Inverness Firth, and saw her out and about with a couple of 'gents' aboard. In fact they came on past me and asked if I was OK! I'd 'hoved to' by 'Middle Bank' as I was fixing 'something' or other.
Can't help with who they are though.
It is a Seawych 19, 1976 or so. I built one from a kit. excellent little boat as a starter. this one has non standard windows - as did mine because the originals were set in rubber channels which apart from looking crude were difficult to fit and keep leak free. Hope the owner manages to retrieve it safely.