Very brief update.
Aside from the wheel arches, the next major issue to rectify was that the firewall did not line up with the rear of the engine bonnet/hood opening:
Added a piece of styrene to the rear of the engine opening and filled resulting gap between top of firewall and body with epoxy putty (Wow! I didn't realise how old I look in this photo..
):
Really happy with how the rear of the engine opening came along:
I also wasn't happy with how bulky the moulding for the windscreen frame was so I have sanded and filled this area and will pick out the frame with chrome BMF.
Next I will add some detail to the underside of the bonnet/hood and then add some hinges.
Cheers,
Anthony