Just listened to the Can You Brew It show that re-brewed Mirror Pond Pale Ale, Fish Tale Alt, and the homebrewer's attempt at cloning Elysian Night Owl Pumpkin Ale. In the homebrewer's version (Tim?), he mentioned that he used Wyeast 1968 as his yeast. I attended a WAHA event in Seattle at the Elysian Brewery, hosted by Dick Cantwell, founder of Elysian, where Dick talked about Elysian and provided recipes for two of their beers -- The Immortal IPA and the Avatar Jasmine IPA. For both beers, the recipes provided by Dick indicated that Elysian's yeast was Siebel BR 96. Dick's recipe notes say that if you can't get the Siebel yeast, that Wyeast 1056 would be the appropriate replacement. To me, all of Elysian's beers have the same yeast character, so during the brewhouse tour I asked Dick whether they used the same yeast for all of their beers, and he indicated that they used only the single strain for ALL OF THEIR BEERS, which is the Siebel BR 96.
Checking Wyeast's attenuation chart, Wyeast 1056 has an attenuation of 73-77%, with Wyeast 1968 at apparent attenuation of 67-71%, so perhaps that could account for the difference in sweetness between the clone and commercial examples. At any rate, Cantwell says that Wyeast 1056 is the Siebel BR 96 equivalent.