Well that was a 2 minute job that took nigh on 2 hours to sort!
After unsuccesfully attempting to remove the door from the hinge in the vain hope it may swing open, I dsicovered that if you remove the bottom plate from the camera, the bottom of the latch mechanism is revealed, push it in and hey presto the door swings open.
But as if that could be the end of the story, oh no. Turns out that Minolta thought it would be a good idea to put a detent on the rewind spindle, just in case it should drop into the empty film chamber if the crank is removed (why they though this important is anyones guess!). What does that mean? well it means the spindle needs to be fitted with a special tool.
If you shine a light into the chamber and look down the hole, you will see a piece of wire across the hole, which when in use sits in a nice little groove in the spindle (I did wonder ehy it had said groove after removng it). This means you cannot simply push the spindle back up, as although the wire is sprung, the end of the spindle is not tapered, therefore has no effect whatsoever on the wire.
After much faffing around with paper clips and what was once a G string on my bass, I eventually hit a brain wave, and made a taper - from PVC tape. I wrapped it round the threads untill it was flush with the spindle major diameter and fashioned the end into a cone, voila the spindle now goes through the hole, and I can fit the crank back on and forget I ever tried to tighten one measly screw. :bang:
(On a side note the ISO dial is now fully sorted, but the air damper is next for attention)