I’ve found a school record for Alfred Edward the son of Walter and birth date is right.
I still think you should buy the marriage certificate though. Just to be 100% sure.
So..there is quite a lot of information available. Walter and Caroline had a large family.
I don’t want to spoil your fun so won’t post, but ask if you get stuck.
Here they are in 1911 to get you started
https://www.familysearch.org/ark:/61903/1:1:XW5S-QVNNB Walter has been transcribed as Walter G, but he signs at bottom as Walter James