Hi Sue,
I found your John Richardson on the '51 census, but could not find him on any later reports.
Do you have his death?
Do you know if he emigrated or left Scotland?
I did a search on SP for any John Richardson who died in Scotland from '51 onwards, both OPR and post '55 there were only a couple, but need more info to narrow the search.
I finally found my own John Richardson's parents through the MI's and Kirk Seasons for Kirkpatrick Fleming,
but it did take me over 5 years to find him...

.
The parish records for Dumfrieshire are very poor, and it sometimes feels that it is pure luck if you find who you are looking for, plus the surnames Richardson and Bell are
really common in Dumfrieshire, I've a few of them too.
Yours Jane.