Larry, many thanks for your reply. I knew you was the right man to obtain the answer from:-).
Of course you're right. It was McCredie. There is a shot (that I do not have here) that portrays Omobono Tenni while overtaking the no.92 during the Senior TT (I think the shot was taken on the straight after Quarter Bridge and before Braddan). Now I know it was McCredie, thanks.