Overview
John the son of Henry and Ellen Mawdsley took over his parents’ Grocery business and then presumably converted it into a Jam Making business, in Princess Street Wallgate where they originally lived. Baptised as John Barton (as he was born before his parents were married), he later adopted the name John Mawdsley.
Founding
The Jam Manufacturing business was established some time between June 1882 (when John was still a Grocer on his son Thomas’s birth certificate) and August 1884 (when John was a Jam Manufaturer on his son Richard’s birth certificate). At this time the family were living at 43 Princess Street Wallgate where the Jam manufacturing was probably also done before John took over a factory in Princess Street, presumably the old Princess Street Mill (according to John’s obituary in the Wigan Examiner).
By the 1891 Census John and his family were living in Mill Yard Princess Street, which is presumably somewhere in or near the “Premier Jam Works” since that was built on the site of the old Princess Street Mill, as shown in this 1890 map of Wigan. The invoice shown below proves that the Mawdsley business was run from “Premier Jam Works”.

John rented the area of the Jam Works, and in 1894 the Freehold of the Jam Works was put up for sale, this from Wigan Examiner of 14th July 1894

John Mawdsley Ltd
In February 1913 the business was registered as a private limited company under the title John Mawdsley Ltd (according to John’s obituary in the Wigan Examiner). This Christmas Pudding advert must therefore come from after that date showing the company sold things other than Jam.

There is also this sign

And this invoice from 1937, which shows the factory was called Premier Jam Works.

No other records of John Mawdsley Ltd can be found on the Internet.
Southport
By the 1901 Census John and his family had moved to Southport, but the Jam Manufacturers stayed in Princess Street Wallgate.
John Mawdsley

John was the owner of the John Mawdsley Ltd business from its founding to his death on 10th January 1919. He died of Heart Failure on a train that arrived at St Lukes Station Southport, as he was returning from the Jam Manufacturers in Princess Street Wigan (as described in his death notice and obituary in the Wigan Examiner, which also states his son Henry was on the same train, but in a separate compartment).
See also this chronology from Wigan World that reports the death of Mr Charles John Wood the secretary of John Mawdsley Ltd for over 40 years, in November 1935. Charles John Wood was the brother of John’s wife Mary Jane Wood.
Thomas Mawdsley
John’s second son Thomas was appointed Chairman and General Manager sometime after 1913 (according to John’s obituary in the Wigan Examiner).
Henry Mawdsley
John’s first son Henry was also a director of the John Mawdsley Ltd business after 1913 until his death on 2nd June 1944 (see this chronology from Wigan World). Henry had no sons.
Richard Charles Mawdsley
John’s third son Richard was also a director of the John Mawdsley Ltd business after 1913. Richard had no sons.
Frank Mawdsley
Thomas’s son Frank was recorded as a Jam Manufacturer in his marriage certificate and in the birth certificates of his children until his last child was born in August 1966.
End Of The Business
In Frank’s death certificate of April 1983 he is recorded as a Launderette Proprietor, so the Jam Business was likely sold between 1966 and 1983, though no record can be found of this.
Current
The site of Premier Jam Works was taken over by a furniture showroom and is currently a bed warehouse.

Deakin’s
There was another Jam Manufacturer on the other side of Chapel Lane Wallgate Wigan (in Bradford Place) called Deakin’s, founded around the same time but looks like a bigger operation. See Deakin’s Jam Manufacturing. A Mr and Mrs W K Deakin sent flowers to John’s funeral, according to report in Wigan Examiner.