360 Timing Mystery

That balancer doesn't look original. I think it's aftermarket and who's to say it's ment for this engine.

Pull the nr1 sparkplug and stick a blunt screwdriver or something in it to feel if the piston is indeed near TDC.
Turn the crank left&right to see if the screwdriver comes up more or not.
This is a crude way of locating/eyeballing the whereabouts of TDC.
The proper way would be to make/install a piston stop, rotate the engine both ways until the stop blocks the piston, and mark the balancer exactly halfway in the unswept area for TDC.