Ok I know who my Smiths were..... I found em on the census over the years, and most recently on the 1911 Census.

Extract of cert :

Samuel Gray (2xgreat Grandad) 65 Horse Dealer b.Washingborough Lin (near enough it was Branston but he usually says Metheringham anyway).
Deliah Gray (2xgreat Grandma nee Smith) 65 Ludborough, Lin
Mercy Gray (daughter of above) 21 single Boston Lin
Mary Smith (mother of Deliah, nee Brown) 93 Widow

So far so good, they claim to have had 10 children of which 6 are alive and 4 are dead.

then we go into unfamiliar territory...
because with them are:

Frank Clark son-in-law, age 32, wid Horse Dealer b.Messingham (Brigg)
Samuel Clark nephew age 4 b.Horncastle
and Richard Gray, grandson, age 1 b.E. Kirkby.

Now the children I have for Sam & Deliah are:

Abigail b.1872 no other info a death listed 1872 sleaford Dist which could be her.
Ambrose b.1873 Married Harriet Rhodes (and later Matilda Rook nee Wiles)
Maria b.1876 later known as Mary Ann m.William Henry Troops
Sarah b.1878 no other info
Thomas b.1880 married Ann (Nan) Forrest
Mary Ann b.1883 later known as Ann, married Frederick Charles Troops
Mercy b.1885 - still single on 1911 census.

Now obviously this doesnt add up to ten, so did the others die in infancy, and with a surname like Smith how on earth would I find them?

There are only two known possibles for a wife for Frank Clark - Abigail and Sarah.

Why cant I find Frank Clark? Ive tried the Francis Clarke as well, and tantalisingly, a William F Clark turns up on census with no apparent links but seems I dont know, my genealogists nose is abuzz.... anyone have any knowledge of the Clark Family who appear to have been travelling the Lincs area in the 1800s? please shed light for me.