So, in summary, I'd say it's a good thing that at least the front and rear bushes have the same fitting dimensions - the individual bushes I have can, therefore, be used as a template for fabricating replacements - poly items would be ideal, I'd have thought.
Here's an image of the new subframe.. they're of pretty poor quality overall and very light
IMAGE 1: Top.
IMAGE 2: Bottom.
By the way, I'm no engineer, I've just done my best to take measurements using the fairly basic tools in my possession. Drop me a PM if I can provide any more useful info.
Cheers,
Karl.