On the marriage certificate (dated 4 Aug 1930) it has Ernest's age as either 24 or 34 (Illegible). If he was 24, that would put his DOB around 1906, whereas if he was 34, it would be around 1896. I'm leaning towards 24 as both the record that Liz has and the one I found suggest a birth after 1900. Also, I cannot find any record for an Ernest William MAY born in 1896.
My record is:
Philip MAY Married M 23 1888 Iron Moulder-Blast Furnace Tonbridge Kent
Chrissie Elizabeth MAY Married 4 years F 22 1889 Folkstone Kent
Ernest William MAY Son M 4 1907 Sundridge Kent
Mildred Elizabeth MAY Dau F 3 1908 Tonbridge Kent
Gracie Beatrice MAY Dau F 2 1909 Tonbridge Kent
Philip MAY Son M 0 (2 months) 1911 Tonbridge Kent
Kate GILBERT Boarder Single F 22 1889 Machine Hand Tonbridge Kent
Reg Dist: Tonbridge
Address: 33 Priory Walk
County: Kent