working back from his death reg on FreeBmd
Llewellyn M Francis 60 june qtr 1930 Merthyr Tydfil vol 11a pg 697
finds him on the 1901 census
2 Jubilee Cottages, Penydarren RG13/5030 folio 123 pg 6
Llewellyn M Francis head mar 30 hairdresser
Eleanor wife 29
Sybil May dau 7
Olivia Jane dau 5
Elsie Muriel dau 4
Thomas Jones father-in-law widower 62 stone mason b. Carmarthenshire, Llanllwni
all born Merthyr except where stated
No more children showing on the 1911 census.
marriage ref
Llewellyn Martin Francis june qtr 1893 Merthyr Tydfil vol 11a pg 863 with Ellen Jones on the same page
He's on the 1891 census with his parents David & Jane in Gellideg RG12/4433 folio 95 pg 34
I'd think that the local newspapers for the time would have info about the local mayor. You could ask Merthyr Tydfil Central library
http://www.merthyr.gov.uk/Home/Leisure+and+Tourism/Libraries/ooops - corrected wife's age