<Only 9 (23 if you include middle names). But surely you know where you father was born?>
I found him. He was born in Queen Charlotte's Hospital, St Marylebone, County of London according to his registration of birth. He had no middle name. When I input the district as well as county I get 79 results for Jack/and or John, none of which match. If I narrow it down to within one year of 1908 I get 47 results and narrowing it even further to just 1908 I get 26. They all just say John. The second name is a possibility, it says parish Styal which is not on the birth registration, but it also says County of Cheshire which is where the naval training place was in 1924. Hovering over just says John is on this record.
I paid the $4.41; now I have to figure out just where the actual information is - piece, etc. And copy/paste it. There appear to have been a great many boys at this place; he is listed as #329. It also says his father is dead rather than unknown; most of the boys' names say that.
ETA: I clicked on print record, it said loading image but nothing further. I copied it to my hard drive and tried copying from there; I got the right-hand side of the page only, with the names missing. Both portrait and landscape.
I think I will try looking at the page for Alice as well.