I would say there are around 11 decent manufacturers left in Northampton. (Plus Dr Martin still make some)
Crockett & Jones
Joseph Cheaney
Edward Green
John Lobb
Church’s
Trickers
Barkers
Alfred Sargeant
Grenson
Jeffery West
Loake
I can’t comment on all as don’t own or haven’t seen in person shoes made by Alfred Sargeant, Grenson or Loake.
Cheaney are very good and well made, compared to some of the other Northampton brands their prices are reasonable I have a few pairs.
My person favourites are Crockett & Jones. One of the better makes at sensible-ish prices. Prefer them to some of the more expensive brands.
Edward Green are one of the best, along with John Lobb. But you do pay for the privilege, even from the factory shop.
Trickers are also very good but not one I’ve been inclined to buy, prefer the other brands.
Church’s are on a par with Crockett and Jones but they are more expensive and I’ve always felt they aren’t actually as good as they think they are, but that’s a personal thing.
Barkers are okay but only really the more expensive Barkers Black range is the top quality.
Jeffery West make some in UK but others in Italy. They are a bit different and not the normal English shoes.
If you are in the Northampton area Crockett & Jones, Tricker’s, Barkers, Edward Green, John Lobb, Cheaney, Church’s and Jeffery West all have factory shops. Friday is the best day to do the tour as they are all open that day.