Back in the 70s and 80s, a large number of pre Wimbledon events in places like Beckenham, Surbiton, Bristol, took place and one venue was Edinburgh's Craiglockhart club.
the event wasnt always played (was it the Scottish Championships) and the quality of the field was up and down - the event didnt carry ranking points.
In 1989, they attracted McEnroe, Connors, Gerulaitus it seems - I found this video on the internet - it seems STV didnt have rights to the final as they actually show little action of it, but it is a nice story anyway. Mcenroe went on to win the event