Yeah I think it must have been a copy of the 'Adopted' birth certificate of 1928, everytime the GRO or RO issue certs they have a unique reference number for legal reasons obviously.

Its going to be difficult Joan I'm not sure you're going to find out where he came from unless like someone else pointed out, which I think is very possible, that he came from within the extended family and with him being so young it is very possible.

Its a shame his son hasn't responded.

But I expect the clues are there.

Edit to say: I don't know anything about adoption issues, but have you got that birth cert (the 1928 one) sorry if its obvious with the information you've given but I do get in a muddle sometimes.

Also was Henry Wicks married before Caroline or am I getting him confused with his father?