The B section belt definitely won't work.
The belt been sliced at an angle indicates the belt is running on the rim of a pulley , the glazed look can be normal on a correctly installed belt.
Check belt pulley alignment - should be as straight as posible
Belts tend to lose chunks if they fail, slipping creates polished belts and pulleys - think smooth pulleys rubbing at high speed on the belt.
Rubber shavings indicate a shredding cutting action OR a normal vee-belt been used where a wrapped belt is indicated.
Imagine the engine doing 3300 rpm trying to get heavy stationary blades up to speed in a fraction of a second. The wrapped belt will allow the slip necessary to accelerate the blades without damage to the belt.
Lastly check there is nothing (stick,stone,seed, nut etc) lodged in a pulley vee - don't ask me how I know
Cheers. Have a great weekend
