Gday Ralph
Almost bought this kit yesterday...
I'd start with rebuilding the engine door handles etc.
I'm quite sure there's a PE AM set for this, so maybe search on that as to what's replacable? (But by no means correct!)
I think folk gripe about the roadwheels maybe, and I know there are a few AM sets out there in resin...
Oh, this is just the M20; the M8 was known as the greyhound, with the turret... And as such more interior will be showing where I'm certain the aftermarket sets will come into their own!