I've just sold my Carlton Ten. Not a lot of info out there on this particular model, they seem to be quite a rarity. Not sure about your frame number though, F would indicate 1957/8 but I don't think the Ten was introduced until 1966.
Hmmmmm there should be a way - using mathematrics to work out how thick the tube is - those figures look a little wrong as the tube would be 2.7mm in thickness - or am i too tired to work that out? That would be a think tube!!