I’m in fact Lancashire born and bred, which is probably why I’ve always had a very soft spot for Neville, who I’m pretty sure comes from my neck of the woods (the Blackpool pier incident, the fact that his grandmother is a typical Lancashire matriach, the fact that he has a traditional Lancashire surname, and the 400-year-old association between Lancashire and witches).
It may help if I expand (excuse me if I fill in more, rather than less detail—I’m not quite sure how familiar you are with British geography.)
I’ve some vague idea JKR had a job in Manchester, once—working for the Chamber of Commerce, I think, so I assume she would be fairly familiar with the area.
Surnames ending in -bottom are fairly typical of East Lancashire/ West Yorkshire. Slightly old fashioned names such as Algy and Enid are typical of Lancastrians of my mother’s generation (she’s called Edna, but a number of her friends were called Enid).
Lancashire and Yorkshire, being two of the more northern counties of England, are regarded with some suspicion and, indeed, ribaldry by the affluent South East (Vernon Dursley would despise someone with a northern accent on principle). The South East regards the area as being entirely covered by decayed textile mills, and populated by strange people wearing flat caps accompanied by whippets. As a matter of fact, it has some of the more spectacular scenery in the country, as the Pennine mountain chain (the backbone of England) runs straight through, forming the boundary between Lancs and Yorks and running up practically to the Scottish border. One of the Westernmost offshoots of the Pennines is Pendle Hill, which dominates the North Lancashire skyline. Although there are a number of industrial towns close by (Burnley, Nelson, Colne etc) it is set in wild moorland. In 1612 Pendle became notorious as a hotbed of witchcraft, when a group of about 20 local witches were rounded up on the orders of one Roger Nowell, Justice of the Peace, sent to Lancaster Castle (which is about 15 miles away), duly confessed to various things including causing the maiming of a local pedlar by setting their spirits on him in the form of a black dog, and were hanged. One of the chief prosecution witnesses was Jennet Device, the nine year old daughter of one of the accused, and her testimony helped to commit her sister, her brother, her mother and her grandmother (who died in prison). This was all written up by the clerk to the court as the “Late Wonderful Discoverie of Witches in the County of Lancaster”. About 20 years later there was another witchcraft trial (with Jennet Device one of the principal accused) but the witches were acquitted. The locals are still very proud of the witchcraft connection, for example at one of our favorite Pennine pubs, the Strawberry Duck, the usual bitter is Pendle Witches Brew (the guest beer is Dark Assassin, from the same brewery). I think there is a coven or so still operating in the area, and there’s certainly a shop for witches supplies in Barrow in Furness.
Blackpool (where Neville is dropped off the pier) is a large and spectacularly tacky seaside resort in Lancashire where people working in the mill towns of Lancashire traditionally went for the August or July break when the mills were closed for maintenance. Further, many of the same towns ran special late night trains to and from Blackpool on Friday evening (the Blackpool Belles or the Blackpool Steamers). It would be an absolutely typical place for a family in the Pendle area to go on a day trip.
Finally, the clincher was Neville’s reference to his grandmother’s outfit. It reminded me so strongly of my own grandmother that I could picture the air of grim lipped determination that went with it. The typical Lancashire matriach has held her extended family together through one or more wars, the Great Depression, poverty, drink, malnutrition, unemployment, infant death and anything else you can think of, and is still marching determinedly on.
JKR did indeed work very briefly for the Manchester Chamber of Commerce (Scot2002).