Thank you again for the replies.  I do now have the bike back home, the bike shop found some pads which fit, as in they don't extend back inside the forks, they do seem better, though I think I'll have a go at adjusting the height of the straddle wire, thank you for the Park Tools links.

I have checked the rim width with my ancient vernier callipers, these show the front rim to be 24mm (not 27mm!).

I do indeed have the wrong brake/shifters on flat bars, they are Shimano ST-EF35-8 and ST-ET35L, the bike was converted from drops to flats by the previous owner. I gather my options are to change these levers, to something like Deore LX M567 combined shifter/levers or change the cantilevers to V brakes, but again told by the bike shop that this would not be possible, but feel I might do this at some point, just a case of finding suitable V brakes.

Thank you again for all the words of advice and support, appreciated 

If you switch to V brakes, as PH noted, those need different brake levers.

Or, if you want to keep using the same brake levers, you can use one of these:
https://problemsolversbike.com/products/travel-agent

Those are getting harder to find now when so may people use disc brakes instead.

I use those on my Nomad Mk II and on the front on my Lynskey.  On those bikes I am using normal road brake type brake levers.

I am using the longest Tektro V brakes that I could find, they have an arm length of 110mm.  On my Nomad I want as much clearance as possible since I use 57mm wide tires and 65mm wide fenders.  Thus, a long arm length was needed.

Hi, Thanks for the replies,

I'm 6 ft with normal legs and both bikes were made for me. The Nomad Mk2 says on the parts list "MK2 S+S Frame and Fork Set - Yellow - 620M" and the Mercury "Retro Green 580L for 46mm forks". Yes, well spotted, the Nomad is photographed near Lake Ohau in the central South Island NZ. It has spent most of its life in a custom made box in my daughters garage in NZ and was only used by me for a few weeks a year when I visited (and religiously changed the Rohloff oil). The Mercury comes with a spare set of forks with front pannier lugs and front pannier carriers. I love them both for their particular qualities, but I've decided that only my 2020 Raven will accompany me in my dotage.

Again, thank you for your advice. I think I will get all the details together and start by advertising the Nomad on this forum. Oh, and by the way, I live in west Wales where men are men and sheep are nervous, but am also in Cardiff most weeks.

Regards,

Jeremy

I've seen a number of early Club Tours with Mavic T261 rims, so I gather they must have worked OK with the cantilever brakes?  I ask as my LBS tells me the front wheel which sports a Mavic T261 is too wide for the brakes to work effectively, not even if I switch to a V brake.  Opinions?

Thank you

Let us know how wide the rims are (outside, not inside width), as I have never heard of such an issue.

Most brake pads can be adjusted for width by how the washers are placed on the pad.

Sizes?
Both look great bikes and the Nomad one had me thinking where it was taken. NZ perhaps?
I bought second hand from Thorn/SJS quite some years ago. The bike did arrive in tip top condition, having been appropriately serviced. So selling via them does offer a purchaser considerably assurance. Obviously you'd have to pay SJS a % for that.
Alternatively, sellling firstly here, then perhaps via other cycling forums and then other outlets would attract the interest of buyers who already know of the Thorn brand and its reputation. So you'd be advertising to your target group; qualified buyers.

I bought my second Thorn privately as I'd acquired enough knowledge to know what I was buying.
My current one was bought new from SJS, partly funded by the sale of my second one ( new owner rode it to NZ!)
Provenance eh!
Good luck with the sale.