Oh Allan I can so relate to this account! In the early seventies I was a newly-qualified teacher in Bruntsfield Primary School in Edinburgh.
I thank my lucky stars I have quite a good ear for accents and can imitate them, because I often felt the Scots did not like the fact I was English. (In 1973, John McGrath's 'The Cheviot The Stag And The Black Black Oil' came out and I attended a performance. My word, the anti-English atmosphere in the theatre was tangible!)
I spoke in a rather nice Miss Jean Brodie accent, and this plus my Scottish surname (a town up in Caithness) got me through the prejudice.
Also, when doing a spelling test with my pupils, it was obvious to me that words such as 'girl', 'pearl' and 'unfurl' were far better pronounced in 'Scottish'. I always said, girrul, perrril and unfurrrel which gave the children hints as to the spelling. (far better than geul,peul and unfeul which is how they sound in RP)