D24tdic strange noise etc

[slimlavud]

I bought another D24-engined car! I got a 1995 Volvo 940 TDIC auto estate with allegedly 100,000 miles on it - it looks genuine by the car wear etc.
But after I got it, I noticed a smear of red 'Hermetite' jointing compound on the edge of the fibre head gasket and found some cylinder head bolt wrench adapters in the rear of the load bay... never a good sign...
The car ran fine, started instantly, reasonable power, reasonable on fuel, uses almost no oil and a pint of water every 1,000 miles - no leaks or overheating though.

The one day after being left for 7 hours, it seemed to 'lock' and not want to turn over on the starter - just like one or more cylinders were full of a liquid. It started after another try and ran OK.
It now has fallen off in power and has a 'chuff/tick' noise from one cylinder - near the back I think. Still never gets hot or uses much water (done 350 miles since), sounds almost like a worn rocker (if it had rockers of course).

My questions are:

1. Could it have bent a rod and what I can hear is a piston scuffing badly in the bore?

2. Has anyone heard of a rod bending on the starter motor pressure alone?

3. Since the steel head gasket bulletin of 1996, are there any even better gaskets available?

4. Is the Elring gasket that some aftermarket dealers are selling a steel gasket or do I have to buy the real thing from Volvo/VW dealers?

5. Any sources for gaskets etc in UK that are steel gaskets and reasonable price?

I know diagnosing engines by email is like doctoring on the telephone but thank you for any ideas?

Simon, London, UK.