Supershuttle was launched to compete with British Midland, who started offering full service on those routes (against the Shuttle which I don't think had any service onboard at all).

About 15 years ago I had a big desk diary that had a lot of out of date information about the shuttle service in there - long consigned to the bin I'm afraid!

I suspect an e-mail to these people would probably get some decent information back.
http://www.britishairways.com/travel...n/public/en_gb