A club member here had an early 60's Herald Coupe (Aus CKD by AMI) and he had to slam the doors, at a "tweak it day" I fixed the anti burst wedges, realigned the doors and hey presto the door shut with min action, not quite Jag like, but close!
The daughters Mk2 Spit has a closed circular section door rubber not the closed cell type, and that affects the door closure, I need to replace it with a small C section flap pinchweld, but there's only one supplier here and he only sells it in 50 mts rolls $+$+$, at a max the Spit and Vitesse would use 12mts!! I have thought about cutting longways along the bottom the closed circular type and trimming the flap length to create a small C section to see if that helps/works