Unfortunately the shoe museum was closed when I went there, they are now always closed on Mondays.
To start off, I'll tell you about the factory shops I visited. Of course, these are my impressions, ymmv, but I hope to offer some practical information for anyone who is thinking of going himself.
I did try to also visit some factory shops that were out of town and/or of brands that have not been featured in other people's trips before.
One general word of advice, which has been mentioned by others before: do not get your hopes up. If you find something you like at a good price, that is fine. But do not expect there to be a lot of choice in your particular size or there to be ridiculously low prices. Times have changed and at some shops prices have changed a lot too. Generally speaking, if you have to go to London or anywhere near Northampton anyway, it makes sense to allocate some time to go and visit factory shops. If you have to travel far and this would be your only goal, it might not be worthwile to go. Also, some of these shops are up to 30 minutes drive from Northampton. If you do not have a car there, that could be a problem. If you do have a car, use a satnav (gps) and type in the postal codes rather than the streets of the shops to best get to them.
First, for the makers outside of town.
Grenson: I went here first, on the way to Northampton. Unfortunately the factory shop they had in Rushden (30 minutes from Northampton) is now closed.
Alfred Sargent: Also in Rushden, they do not have a factory shop, but the factory tour there was a very special experience. I'll save that for later.
Barkers: In Earls Barton, which is between Rushden and Northampton. Their factory shop was definitely the biggest I have seen. There were several female staff. They do have quite a lot on offer in many sizes, also in F and G fittings. Prices were around GBP 80-120 and the shoes generally looked fine, although they did not really appeal to me. These lines are said to use imported skins, but the uppers looked quite passable. There are slight seconds and lines that are out of production. They also have quite a lot of women's shoes, slippers, some belts and other accessories. On a small separate rack, there were Barker Black seconds, their premium offering. These were GBP 150 for shoes and 175 for boots. There were some nice shoes there but a more limited choice, maybe some 20-odd shoes and boots together. If you have the chance to visit, you might find something there.
Cheaney: In Desborough, 30 minutes north of Northampton. For me, this was definitely the best shop. Cheaneys is now owned by the Church brothers. They make all their shoes in Northampton. They also manufacture a lot for other brands and labels. They had many good quality shoes to offer in various sizes. If you are a size 8UK, you are in luck, because sample shoes for new styles are always made in size 8. These are then sold in the factory shop, they are not seconds. They had many shoes which were either sales shoes or slight seconds. The older gentleman who ran the shop was very friendly, knowledgeable and helpful. There is a lot of pride in what they make and I can say they are good quality shoes. They use good quality uppers. The colours and burnishing were really nice. I saw a lot of shoes I liked, and ended up buying two pairs, a pair of country brogues in mahogany with a dainite sole and some tan suede brogues with a crepe sole. I have wide feet myself (G-fit), so I believe there is even more choice for others. Ok, these are not EG, G&G or Lobbs, but definitely very well made and do not cost the world. I even got compliments the next day at other shoe places wearing the country brogues. Average prices were GBP 100-130, up to 150 for balmoral boots. I feel it is really worthwile to go here. They are working on a new website, and sales/seconds could also be offered there in time.
That's it for now, next up will be some of the factory shops in town. I only shot some pictures at Cheaney's:
The factory itself, under British ownership once again, proudly flying the Union Jack.
Across the road, the factory shop.
Large selection as you can see with many nice shoes to choose from.