Jim’s right about the wheels, they are a conversion. Your MT is post 1966 and pre-1971 (engines changed to white around then), Handle mounting changed then to the single bolt type like Titan ones, previous ones had 3 bolts. To get a good idea of the age of the machine you can find out the date of the engine, it’s on the cowl under the air cleaner, and it’s the bottom set of digits. It only works if you’ve got the original cowl still on there.
https://merrytiller.co.uk/merry-tiller-history.htm