Nice project.
Body is probably earlier than 1933 going by the single D cutaway behind the radiator. Also it should have a combined oil and petrol tank.
As rough rule, Matchless engines were fitted from 1934 onwards.
I'd suggest that you run the chassis number and engine number past the MWTC Registrar. Chassis number should be on the gearbox flange and begin with the letter Dxxxx. If you are very lucky it will also be stamped in the St Christopher medallion on the dashboard
Hope this helps
Arwyn
