Mi Mike / John.
I did my CS by religiously following Butch's tutorial when all else was giving less than desired results, worked like it says on the tin!
It helped me work out that the camshaft was a tooth out even though I'd installed it 3 times exactly to the marks. In the end I put timing marks on the camshaft retaining collar as well.
Another good tip from Butch is to make a pointer and fix it somewhere around the injector pump, close to the rim of the flywheel, then mark that at TDC. derived from the engine, not any existing marks on the flywheel.
Having done that wrap a piece of thin string several time around the flywheel and cut the ends dead level. Unwind it and measure it. divide the length by the number of turns, then by 360 (the more turns, the greater the accuracy) Mine was 5.13mm, from memory.
You then have the distance on the rim of the flywheel for each degree and with a suitable marker mark off each each 'event' - Inlet valve opening and closing, ditto exhaust and IP timing by multiplying the degrees before or after TDC by YOUR result, not mine, and you'll have the best timing wheel ever. Bigger IS better in this case.
Then you'll know exactly what's happening when by watching the cam followers and listing for the 'creak' of the injection pump
Once I was satisfied I marked the flywheel with a chisel and small letter punches.
Cheers
Stef