I'm at a bit of a disadvantage not having seen this advert, but, if the cyclist is wearing glasses, and you can read "Wearwell" then it's Ken Mitchell in the 1955 TdF. Is it the picture of him in the mountains? If so, you can see his front-changer lever mounted on the bars on his left, inside and below his left brake lever.
Best regards
Geoff Margetts,
Dreieich,
Frankfurt,
Germany