The 1891 census gives Thomas' birthplace as Stourport, Worcestershire, and the 1901 as Worcestershire. (Born c1852.) Alice was born Smethwick, Staffs, c1864.
There's no obvious marriage on Free BMD (although coverage for this period is pretty well complete), and with a common name like Johnson you really need to get a birth cert for one of the children, as this will give Alice's maiden name and make a marriage search much easier.
Did Alice definitely have middle name Mary? I noticed these entries, although the first one seems a bit early if her dob is correct on censuses.
Marriages Jun 1876 (>99%)
JOHNSON Thomas
LODER Alice
SPIERS Charles
WILLIAMS Sarah
King's N 6c 607
Marriages Jun 1882 (>99%)
BROWN Walter Joseph G
DEAKIN Alice
JOHNSON Arthur Thomas
KEENE Emma Georgina
King's N. 6c 683
Kings Norton is the registration district for Smethwick.
Births Jun 1884 (>99%)
JOHNSON Edith Eleanor
King's N. 6c 493
Births Sep 1885 (>99%)
JOHNSON Maud Gertrude
King's N. 6c 465
Births Sep 1888 (>99%)
JOHNSON Louisa
King's N. 6c 413
Rambler