BGO (along with the likes of Cherry Red and its sub-labels, and Ace Records) are direct competitors of D-V in the UK, so none of these companies are going to have anything to do with each other.
The nutshell version is that between themselves, Sony, Universal and Warner basically own the the rights to the very vast majority of every popular album released in the last 100 years. Major labels, like car manufacturers, don't want to sell 1,000 of something (it's pretty much literally not worth their time), they want to sell a million, or if they're lucky, multiple millions of copies, something which is probably a rarer and rarer occurrence these days.
One account from Billboard writer Bill Holland in the mid-00's suggested that UMG had something like 2.5 million various musical"assets" (a catch-all for anything that has music on it - tapes, laquers, wax cylinders, etc.) and Sony had in the region of 1.5 million. I'm not suggesting that 1 asset = 1 album, but it gives you a kind of ballpark for considering what these labels are dealing with. So what do they do with the tens (or hundreds) of thousands of albums they simply don't have the time or money to devote to reissuing? They license them out to reissue labels like D-V. Think of it as a kind of mutually beneficial type of outsourcing - because they're fronting the money for each reissue, the reissue label assumes all the risks involved, but at the same time that same label will (hopefully) also have unique knowledge about how to package/remaster the reissue in a way to maximise its appeal to their demographic, and also will also likely have a loyal customer base who will buy their products sight unseen (or unheard) based on their satisfaction with previous purchases. D-V is certainly building up that kind of reputation here, and there are plenty of fans of the stereo audiophile reissue labels like MoFi, AP, Intervention, and AF (when they were still around) both here and over on the Hoffman Forums.
I don't know the contractual nitty gritty of a licensing agreement, but it's my general understanding that the licenser (ie Sony) grants the licensee (ie BGO, or D-V) the exclusive right to sell their own unique version of an album for an agreed-upon number of years in whatever territory the licensee is located. It may vary from case to case, but generally the licensee has a certain number of discs pressed as part of the initial batch, and then they can order represses if the title sells out, if they're still within their license period. So basically, this is a long-winded way of saying that if BGO is selling stereo CDs of Andy Williams albums that also had quad versions, they're off the table for D-V until BGO's license with Sony expires. Knowing if or when that's happened is a tricky thing - some titles go out of print really quickly, while others seem to be perennially in print with the same reissue label, I'm guessing they just re-up their contracts if titles or selling, or maybe they have rolling agreements, I dunno. If you're curious if a title is possibly 'available' for D-V one way of researching it is to look up the album on a UK retailer like Amazon.co.uk (and/or HMV, or similar) and see if it's still available for sale from them, and not a 3rd party seller. If it says 'title unavailable' (as opposed to stock coming soon or something like that) then there's at least a chance that it's out of print - but again you never know because there's always stuff going on behind the scenes.
If you want more insight into what goes into a small reissue label, there's a guy on the Hoffman forums who started a label called 'Rubellan Remasters' - he made a thread over there called "New Classic Alt reissue label: Rubellan Remasters, now open for business!" where he discusses in pretty candid detail (maybe TOO candid, in my opinion) all the hurdles he's faced and his annoyances with all the various major label people he's had to work with. If anything it'll give you some extra appreciation for how D-V has managed to maintain such high quality and a high volume of releases, with a minimum of self-congratulatory back patting about their achievements...aside from posts like this where I get on my soapbox a bit.
