Chally604
By suggesting you enquire here I was hoping you would receive a few more answers.
I left the Area ATC world in 1980, and the Approach Radar world when LHR's radar function moved to West Drayton in 1993, so way out of date!
No 2 son who is a Swanwick ATCO doesn't 'do' PPrune, but I'm seeing him on the weekend so will show him your query.