But the marriage is online. Ada is a widow, maiden name was Gabell. Plus the Wisemans are on electoral rolls in Hackney, and appear to be findable in the 1939 Register as well.
Where were James Scott's shops? In Rochford? Southend?
In the Essex directories I can see James Scott, confectioner of 1143 London Road, Leigh, and further away, James Scott, confectioner in Purfleet. No likely chemist.
Then James is at 40 Boulevard, Weston super Mare - 1939 Somerset Directory. That is the address they are at in the 39 Register.
Could he have had a family link with Weston? See no evidence, to be honest.
Ellen Ling, Ada's mum, did she marry again to William Fance, and stay in Rochford? There are a couple of entries of a James Scott on the electoral rolls in Rochford, around 1926-7. 1926 at "Renelta", Ashingdon Road. Also there, Alexander Scott. Both only have the parliamentary vote. Don't know who else is there, if anyone (list is alphabetical) May not even be your James though.