If you decide to buy a cert online do make sure you are on the official ONS site @ �7 and not a parasite which will charge �23.
Once you have a name and address you may want to subscribe to ancesttry .com for a free*month* 0800 731 6679.
You will have to give your CC details but they give you a number to phone io cancel before the month is up.
Judicious use of the census information in ancestry. com, alliied with birfhs, marriages and deaths info from the free.bmd website could enable you to make some reasonable progreess backwards in time.
However, ancestry ,com transcripts, (which come from The Natrional Archives) contain far too many luducrous and incompetent mistranscriptions - shame on them.
So beware, and please take nothing as true until it has been properly verified.