+1 on the manual cam chain tensioner.
The shavings in the oil could be from the disintegrating clutch washers, mine was gone at 10 000km and also destroyed the plate that holds them in, had to replace that and the springs as they were also damaged by being so loose. I posted pictures at the time, will see if I can find a link.
You are really doing a great job. How many Km's has the engine done?