This one is a bit of a puzzle because I have this photo in my system as a 1921 Calthorpe 10hp. Having looked further on the internet this car seems to be all things to all men. The four by four louvers on the bonnet suggest a pre 1919/20 and a 10 hp four. After '21 they had lots of thin louvers and more wheel studs. Three studs also suggest pre 1919/20 as does the curved back to a square dickey. Calthorpe recommenced production in 1919 with a new 10.5. Info on the marque does seem confused on the internet but if I have to go with anything, probably a 1920 Calthorpe 10.5 with a Mulliner drophead body. Interesting spare wheel carrier. Regards Vintman