May I ask if you live locally to Darlington or not?
It isn't possible to tell if our family interests may link or not from the info you have given.
The marriage certificate for William Allan to Ellen ? will show who his father was and also his father's occupation. I imagine that the St Cuthbert's Church, Darlington may be the church where William Allan was baptised There are some baptisms on the IGI for St Cuthbert's but the record is not complete at all. Finding out who Wiliam Allan's parents are will be most interesting.
Some of my Allan marriages were in register offices, therefore not to be found in parish registers.
Please contact me directly - Diane.J.Buxton@btinternet.com