My son's 1.4 mk3 Golf, (AEX engine), had a leak from one end of the exhaust manifold / cyl hd joint. Muggins here tried to tighten it up with predictable results


I'm therefore tempted to try putting it back with 4 good studs. it has 3 along the top, (which are OK - centre & both exteme ends) and two along the bottom, (between 1 & 2 cyls & between 3 & 4) - this last one has the broken stump in the hole.
My questions are:
1. Any idea where I can get spare stud(s) on a Sunday?
2. Anything I can use to improve the chances of the gasket sealing with a less than perfectly even pressure on the fixings?
3. What's the chances of it holding on 4 out of 5 studs, if they're all in good nick?