AFAIK they are not "genuine" as in branded and officially warranteed by, but IIRC they simply might come from very same factory and resold at cheaper prices by some .. "private labels". Speedline, or ft86sf "OLM" ones (in past btw also named as valenti, or valenti style, now changed to OLM, probably due some legislation stuff).
Just like tomei vs gruppe-s headers.

Probably same factory, but it could be that Valenti asks for better QC. Here in Italy many had problems with Speedline Valenti's, but IDK if they are the old V1 type or the new sequential.
Strange is that they cost the half even from the ones from Japan...

IMO, basically saying something similar to what you posted, the Valentis that The Speedline sells are gray market Valentis that come from the same factory as those sold by an authorized Valenti dealer.

Gray market goods (also known as parallel imports) are genuine goods purchased outside a manufacturer’s intended chain of distribution and imported to compete with authorized domestic sales, generally at lower prices, i.e., cameras sold by some NYC camera shops without a USA warranty.

The Speedline claims on their website that the Valentis they sell are authentic, and are warrantied by them.
https://www.thespeedline.com/valenti...c-information/

The Valentis I purchased from them were shipped directly from Taiwan to me.