Thanks everyone. I can understand the reluctance to dish out this information publicly but it's all above board (honest, guv!). However, equally I'm not going to discuss on the same forum the precise commercial reasons for my visit.

I have an invitation letter, and have had one before so I know the score about getting on the buses; it was simply that West Drayton would have been by far the easier option for me today. Unfortunately, it does appear that the BA3 no longer runs there (if it ever did), so an alternative route I am taking.