Hi GForce,
This is the only information I could find about your Pettigrew family.
First of all, you quoted an inscription "Erected by James and Margaret Pettigrew" etc:
This is a double lair in Section A 38 and 39. The records I have show the following internments, all dates are dates of burial.
THOMAS H. PETTIGREW, Wishaw, aged 6 months.
Parents - James Pettigrew and Margaret Rankin.
Interred in A38, 30th Nov 1885.
JOHN R. PETTIGREW, butcher, Wishaw, aged 17 years, unmarried.
Parents - James Pettigrew and Margaret Rankin.
Interred in A39, 25th Feb 1895.
THOMAS W. PETTIGREW, Wishaw, aged 7 years.
Parents - James Pettigrew and Margaret Rankin.
Interred in A38, 31st March 1900.
THOMAS PETTIGREW, forester, New Monklands, aged 65 years, unmarried.
Parents - Robert Pettigrew and Margaret Wardrop.
Interred in A39, 14th Oct 1909.
JAMES PETTIGREW, Flesher, Wishaw, aged 63, married.
Parents - Robert Pettigrew and Margaret Wardrop.
Interred in A38, 23rd Sept 1911.
That's all for that grave. (And now you have a maiden surname to help in the search)
Also found this - Lair F65 and 66.
ELIZABETH B.C. PETTIGREW, housewife, Wishaw, aged 30 years, married.
Parents - John McCrindle and Marion Frame.
Interred in F65, 2nd July 1912.
Lair owner registered as Robert Pettigrew, butcher, 2 Park St, Wishaw.
I expect this is your Papa's mother, so he wasn't quite 6 years old when she died.
Also, for the Gibb grave, that is in section E, number 1552.
STILLBORN FEMALE GIBB, wishaw.
Parents - Peter Gibb and Mary Botham.
Interred in E1552, 4th Jan 1910.
ELIZABETH GIBB, Wishaw, 3 days.
Parents - Peter Gibb and Mary Botham.
Interred in E1552, 1st Dec 1913.
I can also tell you that in the 1895 Wishaw Directory, James Pettigrew owned a butcher shop ( flesher = butcher) in Main St, Wishaw.
Finally, i can tell you that someone else is researching the McCrindle family. If you click this link
http://www.familysearch.org/eng/search/frameset_search.aspThen type in the names John McCrindle and Marion Frame in the "father" and "mother" boxes, then click on Search, it should bring up 4 children in the Pedigree Resource File. Looks like Elizabeth McCrindle was born in Cambuslang. The name of the submitter is there as well. (Try putting in Robert Pettigrew and Margaret Wardrop, plenty of info on them in there too).
good Luck,
Lodger