Cambelt problem 206 1.1 verve '03

[Roadster]

I have recently bought a 206 for my son who has just passed his test last monday. The car needed quite a bit of work & before i got it in the workshop cambelt snapped, the head was skimmed &had 4 new valves, new belt & tensioner pulley is fitted, the timing is set & when turning the engine by hand the new belt overhangs the left-hand edge of the cam pulley by 3-4mm, i've even put the old tensioner back on & still the cambelt overhangs the cam pulley. The only thing i have not re-newed is the waterpump. Could the waterpump pulley/bearing have been damaged when the belt snapped & consequently is throwing the belt out of alignment.
Me & my friend who has 30+ yrs experience on engines are stumped.
Can anybody help??