BRIGG PHONE NUMBERS - WE NEED YOUR HELP

A Brigg business is trying to work out the age of an old item and  might be able to do so if someone can answer this question:

Do you know the timeframe when the Brigg telephone number didn’t have the prefix 6 or 5 on?

If you can help, please email scoopfisher@aol.com and we will pass on the information to the business in question.