I contacted Brett about this some months ago, and he said he “did not know what had happened” to the Connoisseur series of theatre organs. Fortunately Brett had the one DVD I needed to complete the set. It does seem that the samples are no longer available, and I think that's a pity, as the reeds in particular are beautifully even, and the voicing in general is of a high standard. The samples are mono, and the tremulant is in software, but it's still an excellent set.
So far as “premium” theatre organs are concerned, the main contenders seem now to be the “Masterworks” Wurlitzer from MDA (software tremulants), and the Paramount series, which has sampled tremulants, and from that point of view sounds more authentic. I believe another organ is “in the works” from the Paramount team, but it's some while since I heard any news of it.