1851 census Names Index (No addresses or birthplaces given) For Glasgow
There was no Archibald Parker with a wife Agnes
Only one Archibald (snr) born early 1800's
Census taken ST ANDREWS, ward 567, Enum. dist. 4 page 6
Archibald Parket aged 48
David Parker aged 14
I also found an Archibald Parker age 17, but without seeing the actual census, I don't know what the relationship is to the Parker family he is living with
Census taken ST ANDREWS. ward 567 enum. dist. 1 page 18
James Parker age 40
Elizabeth Parker age 40
Catherine age 16
Jane age 14
Elizabeth age 12
John age 10
James age 6
Marion age 3
Next comes another two older Parker boys, which makes be believe they are not other sons, but possibly some kind of relation
John age 19
Archibald age 17
The oldest Agnes Parker was age 32, so I guess that maybe Agnes had already died by 1851