P30 advance lever screws

After half a film shooting, my recently obtained P30's advance lever went floppy, then parted company from the assembly. The retaining screw has worked loose but looks ok. However I can't fix the xxxxing thing as the 2 tiny screws that hold the metal backplate to the plastic lever arm won't budge under normal pressure from an instrument screwdriver. Has anyone had this problem and more importantly is there a simple solution?

I'd guess that these were done up by the Asahi works sumo team (I keep finding parts on cameras which appear to have been tightened with a torque wrench). Try a tiny drop of lighter fuel on them as this can sometimes break the friction and enable you to turn them.

I've also had success with an instrument screwdriver and a pair of small pliers. Grip the screwdriver with the pliers, then while jamming it hard into the screw head use your free hand to attempt to turn it. The extra leverage may help (or may equally shear the screw off, so be careful!)

Just in case you need it, service manual here;

http://pentax-manuals.com/manuals/service/p30_service.pdf

Password is 'Pentax' - note high case 'P'.

Also, here's someone who had a similar problem;

http://forum.mflenses.com/pentax-p30t-broken-advance-lever-t29255.html

Well, got it done at the weekend!! This is how:
Take a micropoint soldering iron (free of solder) and place it on the head of each of the 2 screws that hold the metal plate to the plastic cover for about a minute. Take care not to slip and damage the plastic.
Then place the assembly in a freezer for 10 minutes.
Try the screw with a precision screwdriver if still tight repeat process until successful. One screw came off first time the second needed another cycle.
Whole assembly now refitted to the P30