I see this ride listed on the old IBA Certified Rider list: Mark Cavanagh Lancashire 06/19/10 Moto Guzzi Stelvio 1,549
But can find no mention of you on the new IBA Ride List accessed via the IBA eStore (which shows member numbers as well as ride info).
Hopefully the IBA UK can dig up your member number.
edit - You might also try looking at your account info here. Click on your user name at the upper right, then select "account details". There is a spot for your IBA number. Not sure if it's auto filled, or if you needed to input it yourself.