This 4mm. scale Conversion Kit to produce a LNER/BR(E) Class J50/4 locomotive from a Lima J50/3 base model was released by Jackson-Evans. In addition to the kit there are also two Jackson-Evans etched brass smoke box numbers: “68931” & “68971”. There is a duplication of parts in the kit box which might support the view that the original intention was to undertake the conversion of two base models. There is an original Jackson-Evans instruction sheet included. Other parts/materials will be required depending on the detailed extent of the conversion. Boxed.