Names and Brick Walls

Names:-

Menzies:-

Father - George - Comb Maker
I have at least 6 births for Peter who says he was born in Edinburgh but I can't find him.

Moodie:-

James Moodie and his wife Janet Geddes (Jennet) in the 1841 census. They had 2 children in that census Mary and James. I know what happened to Mary but not James and his parents. All I have is the 1841 census James snr was a house carpenter.

Gray:-

John Gray died between 1848 and 1851 he was a Canal Boatman - Engineman. His son George was born in 1848 but John was not in the 1851 census and his death cannot be found also I have no birth for his or his wife Frances {Fanny} Johnston.