Attenuation of Harvest Cooper's Yeast

I recently did my first yeast harvest from a Cooper's Sparkling Ale bottle, grew a nice colony, and pitched into my first attempt at a Cooper's Sparkling clone. From what I've read, the FG should be at 1.005 or lower. Has anybody that has harvested this yeast put together any data on the average attenuation? I mashed my grains for 90 minutes at 146F and a thickness of 1.5 qt/lb in an attempt to get a highly fermentable wort. My OG came in at 1.051. Doing the math the fermentation requires 90% attenuation to hit 1.005. I did aerate the crap out of the wort, used a healthy starter, and added nutrient during the boil to get the FG as low as possible. Thanks for the help! Does anybody have any experience with this yeast that can offer realistic expectations on attenuation? 90% seems ridiculous to me, but what do I know?

Supposedly Cooper's Yeast is equivalent to White Labs 009:

http://www.whitelabs.com/yeast/wlp009-australian-ale-yeast?s=homebrew

But whether it is actually the same stuff these days would be hard to know for sure. I have used the white labs version and had ~80% attenuation one of the 2 times I used it, FWIW.

i have just done two beers with yeast harvested from a coopers sparkling bottle. the first beer was just a pale ale mashed at 152 or so, OG 1.057, ferm temp mid 60s. it was a poor quality starter but it got stuck at 1.020, i swirled it and tried heating up the carboy a bit but it still only got to 1.017 after a whole month. i figured it was just a weak yeast starter, so made another brew

similar OG, mash temp, fermed low 60s (it's winter), but started it with at least 500ml of slurry. Very active fermentation start, thought i'd be in the clear but it's been 2 weeks and OG is only 1.024...

so far, not happy with the attenuation of this yeast. any thoughts?

I think you were maybe fermenting a little on the cool side