From 1927 most British bikes use an Amal carb. Many interchange with later models and have been! The model number is stamped on top of the flange on the RH or cast in the body on the right. Most parts are in stock. The prefix "AMA" has been added to the original part number to find things back in a database.
Throttle and air cables are all #@%&different
! They alone take up 20 meters of shelf. Please quote type number and check if there is an adjuster screw in the top.