Here you go...
One of the pairs of laces as supplied, the other retro fit. Can't decide. Opinions, please! PM to avoid cluttering the thread?
On many pairs of Tricker's, the last number can be found under the heel cushion along with the UK shoe size - think it's been mentioned on here before but Richard mentioned it to me a while ago when I was trying to find out on what last my Skipton boots were made. He was good enough to post me a couple of new cushions to replace the ones I'd removed.
You'll sometimes see 4-fitting shoes and boots on eBay or find them in charity or vintage shops - I'm assuming that it used to be a commonly-available fitting, but it could just be that all the ones I've seen (around three or four pairs) were made to order. I'm pretty sure that my Skipton boots are a 4-fitting.