I would check your rear wheel bearings are not worn causing negative camber. The little spring clip on the handbrake handle pawl needs to be seated properly to allow the inner piece to slide into the outer case.
Before you put the body on and lose the opportunity have you considered fitting a burton or similar timing case with a modular water pump? It’s an expensive option but worthwhile to avoid future engine out or body off just for what should be a simple replacement. Why have you abandoned the original plan to use mx5 engine and gearbox? I have often thought that would be an ideal replacement and why I originally followed your content. It would provide the desirable 5 speed for the modern world had you been able to make it work.
