HHV does not, but they have never once said "we extract," "in-house extract," or even, "I extracted this." Adam has confirmed this to me that HHV is "basically like Vermillion" in that they do not extract their tobaccos themselves (they get them third party). Hell, I am putting in an order because I will back honesty and transparency over playing the game. As far as I know, Ahlusion drafts/designs most of the extracts (though some are done in-house and they all are born in-house) and have it mass produced elsewhere (see his site article on "Are all your concentrates produced in-house?")
I think some of the problem is that these vendors never said what we attributed to them. Now, it should be stated that if a vendor knows people are saying this and they don't speak out, or have the information provided, that's akin to lying. But, as long as they tell you when asked, or if they've provided the information, there's nothing wrong with that.
As far as I know, House of Liquid tobaccos are made by Concept Liquids.
I asked Darth Vapers some questions recently, and though they responded to me asking if they would talk, they never responded back to my real questions. I may have come on a bit strong though.
NET.com (confirmed), GeJ (confirmed), MoV (confirmed--though, some question remains about Apache), w2v (confirmed) and VCV (confirmed, though not the flavorings).