Searched 1905-1933 could find no marriage.

Do you have your Auntys full name ?
Is it possible they married overseas ?
There were a couple of Meadowcroft marriages ( 1907-10) and a heap of them about 1927-30, but no Eric.
Otherwise its purchasing Eric's death certificate to find his parents. Then its back to easy street

, not too many entries in UK indexes so once you have confirmed his parents, shouldn't be too hard.
Same with Tubb, have a couple of possible candidates and really all we need is confirmation of the parents, re Marriage certificate.
Or you could try trawling thru the shipping lists, have to ask Riley about those.