Merrell Letaher boots: Us or UK sizing

[Rodbelan]

I am just about to buy another leather boot (Merrell, norwegian welt). I wonder if the sizing is UK or US. Some italian boot maker use UK, some use US... I asked the guy on eBay but no answer.
I really have no luck with fit and condition; my last one was a disaster... a Alpine Tele lite; the boot separated from the sole after a couple of trips. Garbage... They were new! But the rubber was altered and they aren't norwegian welt so not much to do...

[lowangle al]

My Merrils from the mid to late 80s fit like they are marked in US sizing.

[Rodbelan]

Thanks Al...