The hubs are Shimano FH-M475. Looks like they do have seals after all, having checked out Shimano's exploded diagram

I have one of these https://www.blacks.co.uk/15998244/lifeventure-thermal-mug-15998244
Available in various colours, from Blacks or Millets (UK).
300ml - which is the right size for a standard coffee from the machines that are now in many small food shops and garages.
Fits snugly in my bottle cages.
Completely leak proof!

I'm really pleased to have it.  I can get a coffee and food, and then cycle to somewhere peaceful to sit and enjoy. 

I've looked at them a couple of times and know a rider with an older model.  One of the things to be aware of is Ridgeback have attached that name to several models, as is the way with most bike manufacturers.  Any comment on anything other than the specific model you're looking at, may not be relevant.  For example - I'm not sure it is Reynolds tubing, the previous model was and was named as such in the specification, the current model just says steel frame.  I'm not a label snob, most Thorn bikes have their own tube label, but more concerning is it doesn't say anything other than it's steel. Thorn's label says "heat treated, double butted cro-mo" which is more relevant than the brand.  Now I may be wrong, but if something that's a major selling point isn't specified, I'm going to assume that it isn't.
Previous models did have great reputations:
https://tomsbiketrip.com/ridgeback-expedition-review/
https://www.bretonbikes.com/homepage/cycling-article-blog/162-ridgeback-expedition-26-touring-bike-2016-review

There's not much choice for this sort of bike, at this price point, which makes me wonder if Ridgeback have put price before function rather than the other way round.  The Thorn Nomad Mk3 can be built 26" but is more than double the price.  Oxford Bike Works have a couple of models that are a bit cheaper. If you're not committed to disc brakes, there's some real secondhand bargains about, I have to keep resisting bikes I have no use for.

I’d swap out the wheels for a handmade set from SJS for around £200

It might not need it, a large part of wheel failure is down to poor build, usually machine built and not properly finished.  You can do this yourself, no special skill needed, just a spoke key and some knowledge (Plenty of youtube guides).  Or a decent bikeshop can do it for you for a fraction the cost of replacements. 
People approach their purchases in different ways, if I'm sure what I want I'll research what's best and then work out how to afford it, with the expectation that I'll keep it long enough to be good value.  If I'm less sure I tend to look for bargains with the idea that I could upgrade later.  I don't always get it right of course, but the Ridgeback falls between the two, i couldn't see myself buying it.

Why the insistence on a 26" wheel? This size is regarded as increasingly obsolete as the industry has moved to 27.5/650B and 700c, and you would have less choice of quality new tires.

A Sherpa would have been my first choice but as they haven’t been available for a while now, I’ve been looking at alternatives. Not many (affordable) 26” wheel steel derailleur bikes out there but have settled on a Ridgeback Expedition, which ticks most of my boxes - flat bar, 3x9 drivetrain, 26” wheel, Reynolds 520 frame tubes, disc brakes, available in XL... They can be had new for around £1k. I’d swap out the wheels for a handmade set from SJS for around £200, plus a Brooks saddle, and would live with the rest of the bike, which seems reasonably well equipped for light-ish on and off road touring in Europe.

Anyone with any experience of these bikes? Either way, any views would be much appreciated.