Just my opinion, but If your picts of your VB V2 and FT V5 are your actual Vamos, the V2 is chrome plated brass while the FT V5 is brushed SS.
I own 2 SS V2 Vamos, 2 SS V3, 1 SS V5 and have bought several more for family members and friends (6 or 7 total). None have had a bright finish.
I could be wrong but I don't think so.
The difference in height (length) is due to the addition of the V3 threaded head to the v2 body. The studded top cap is obviously taller than the V2 top cap.
Nope, it's stainless. When I first got it from Vapor Break in March I wasn't sure if it was chrome or stainless, because I was expecting a brushed finish and this was polished, but not really as shiny as I thought it would be if it was chrome. But a close look inside and out convinced me it was stainless. After nine months, its got some wear that shows it's not plated, but really is stainless. It's not really as polished as the picture makes it look, but it is a smooth polished stainless steel.
Maybe I have a collector's item?