Alan,
I don't have the records for 1903, sorry. What I have ends at 1901, then begins again at 1906.
However, there are quite a few children interred in Cambusnethan that may be of interest. Some are for James Maxwell and Susan Pollock, but they are in the same grave as children for John and Sarah, so could it have been 2 brothers married to 2 sisters?
The first 3 are all buried in common ground -
AGNES MAXWELL. Torbush, aged 9 months.
Parents - James Maxwell and Susan Pollock.
Interred 3rd December 1863.
AGNES MAXWELL. Newmains, aged 11 months.
Parents - James Maxwell and Susan Pollock.
Interred 9th October 1867.
JOHN MAXWELL. Gallowhill, aged 3 weeks.
Parents - John Maxwell and Sarah Pollock.
Interred 13th July 1871.
All of the following seven are buried in the old "Private" burial ground next to the churchyard, the plot is number 552.
ELIZABETH MAXWELL, Morningside, aged 14 years.
Parents - James Maxwell and Susan Pollock.
Interred 8th September 1873.
WILLIAM MAXWELL, Morningside, aged 2 days.
Parents - John Maxwell and Sarah Pollock.
Interred 14th October 1884.
ELIZABETH MAXWELL, Morningside, aged 3 months.
Parents - John Maxwell and Sarah Pollock.
Interred 23rd April 1886.
SARAH MAXWELL, Morningside, aged 3 months.
Parents - John Maxwell and Sarah Pollock.
Interred 29th March 1889.
NEW BORN MALE CAMPBELL, Morningside, aged 5 hours.
Parents - James Campbell and Ann Pollock.
Interred 25th January 1890.
WILLIAM COLQUHOUN. Morningside, aged 20 days.
Parents - John Colquhoun and Susan Maxwell.
Interred 3rd September 1895.
JOHN MAXWELL, Morningside, aged 5 weeks.
Parents - John Maxwell and Agnes H Davidson.
Interred 27th January 1900.
It's highly possible that your 1903 deaths are in this grave but you'd have to check with North Lanarkshire Council cemeteries department.
Lodger.
(For some reason I was unable to highlight the last few names, the text box is jumping all over the place, and I haven't touched a drop all evening - honest!)