Hello AD, sorry to disappoint you, but the F.3 model is 100% original in any of its parts, airbrakes, wings, fuselage... whatever.
I think I know for sure because I did the model from scratch, as I ALWAYS do(the different screenname on this board is actually a bit misleading, but you can get in touch with me on CAce forums if you like).
The fact that many parts "look" the same it's because, well, they ARE the same on the real plane, why should I have made them different?
I don't have your original GR/IDS model, best of luck finding it
bobrock