FWIW sebs arent customs either, maybe i would say "semi-custom"& irregardless of what MW's "faq" says they arent a custom either, again maybe a semi. IIRC MW's (and sebs too FWIW) have some CNC stuff done to them, which isnt a bad thing, but to me it dispells any hints of being "handmade".
i would hope a $450 folder would exhibit better F&F than a $375 one, custom or production. or at least as good a F&F.
and i say again, theres better stuff around for $450, imho, stuff which has better F&F, stuff with (to me) better aesthetics, stuff which will when ya decide to sell it (if ya do) ya will be able to get your $$ out of better, but if the MW folders "grab" ya they arent bad, but are imho a little overpriced.