Hi Shaun, There is some information about The Raven Engineering Company on the post about my Farmers Boy Minor……. I have 2 of these machines, one fully restored and one in its working clothes. Both mine are fitted with Villiers MK12HS engines. There should be a production number stamped into the large plate at the base of the handlebars, where they bolt to the machine. Unfortunately there doesn’t appear to be any surviving factory records to date these machines, the company changed hands and name a couple of times before going into liquidation. However there is often a date stamped on the engines flywheel. This will of course only give you the date of the engine, and if its been changed at some point will not really help date your machine.