I think that with the help of a Dutch friend I’ve solved the mystery of my model.
The second line of writing on the wing says: STRAAL+T, which means that the complete text would be: Fokker Straaltrainer, which means Fokker jet trainer. However, with its narrow fuselage and single cockpit, the one thing that the model certainly does not represent is a trainer.
My friend’s suggestion is that it is actually a Verkuyl NATO recognition model of the Yak-19. The latter is certainly very similar in profile and has an identical tailplane/fin arrangement. The wings on the Yak are set a bit higher and the span is greater but since the aircraft only ever flew as a secrecy-enshrouded prototype, it is likely that Verkuyl was working from provisional drawings. Subsequently, someone has looked at the model and because of its similar configuration, wrongly labelled it as the S-14.
We’ve still got ex-Fokker contacts thinking about it, but I think we’ve probably got our answer.