1999 Vauxhall Astra timing mark

Engine Mechanical problem
1999 Vauxhall Astra 4 cyl Two Wheel Drive Manual 137k miles

I have no visual timing mark on the inner side of the crankshaft pully, where one ought to be.
With the head re-seated and the timing belt on, is there another way of obtaining TDC on No 1 cylinder please?