3x 13 cam sprocket bolts are not tty but obviously if you don't have a torque wrench get one! I've read a post where someone snapped the bolt head off from overtorquing.
Oval crank sprocket = matches pulses on belt from actuating injectors for less wear on belt. They should all be on BRM but manual says some early ones might not.
Earlier ones had larger gaps between the sprocket teeth on two side for same effect. I guess the oval sprocket must work better.