That was my thinking too, but I think I've found more places in the UK that sell a 36 leg than here, certainly on the high street at least. A 34 is no harder than any other length to get here, though, while even that can be tricky in the UK; I think the average size sold would be higher, but the extremes are less well catered-for. I think it's not least because there's one brand that has a fashion jeans near-monopoly, who do a 36 but only ordering off their website, with the only company breaking it being H&M, who are one of the ones who've never done 36.

The Dinaric Alps are in what used to be Yugoslavia, basically. I doubt they have too much of a fashion industry of their own.