You are likely still not looking at this thread, but it’s not dimensionally identical to a FISON; it’s approximately .75mm shorter, with a diameter approximately 4mm wider. It’s also better machined and finished than any Leica hood I own from that era. Truth be told.
It’s a lovely little thing, even if it suffers from the stigma of low price. Haven’t finished the roll yet, so don’t know if it vignettes, but I doubt it, from the looks of it. We’ll see.