Ive just seen Benham's catalogue of First Day Covers and theres two from a series entitled Glorious Scotland One of them has the Commando Memorial on the cover with 5 scottish stamps ..one of the stamps has the memorial on the picture! its poststamped at Fort William. Both FDCs are £17.95. The Commando FDC is £15.95 on its own but signed by The Rt Hon Charles Kennedy MP
Theres a Benham website .. I havent looked at it but it must have the FDCs on there