Hope you wonderful researchers can help me with this Brick Wall?

The above chap is the son of 1873 John Manns & 1874 Margaret(Mary) Alice Browning of Gloucester.

I have his Birth Record and Census Records upto 1911.

Cannot pin down a Marriage, Death, Immigration records at all. I even tried Military Record but he would have only been 15yrs in 1914 so seems unlikely (although a lot did lie about their ages!!)

He has siblings:
1895 Rita Mabel Manns
1901 Jessie Manns
1904 Minnie Manns
1905 Lionel Manns
1908 Wilfred Manns
Charles & John Manns died as young children

Grateful for any help thank you

Sylvia Manns