Could you be thinking of the 57ft BR Mark1 surburban stock? Or were they older coaches? Bachmann used to have quite a range of these but there don't seem to be any in the current (2008) catalogue. It might be worth trying www.bachmann.co.uk for information on what they used to have, and then one or two of the larger mail-order places and see if they have any left.
Hornby don't have anything surburban either, alas, and haven't for a long while.
Regards,
John Webb
Hornby don't have anything surburban either, alas, and haven't for a long while.
Regards,
John Webb