Also, which kit do you have. Airfix have done 2 24th Mossie kits, if yours is the FB.VI its possable these are spares parts from the NFII/FBVI kit. But as mentioned, its hard to tell without a pic.
The instructions should have a list of unused parts.
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On the bench: Airfix 1/72nd Harrier GR.3/Fujimi 1/72nd Ju 87D-3