You found something on the web about the CE with a sleeve?Yes, I see that now, when looking about on the www. I see there were two variants or generations of the 156 CE. I am glad that mine does not have the plastic sleeve though I am sure it was considered an improvement. I can get my plastic sleeve fix on my G260 which I like very much.
I have this beat up old G250 that a LDS gave to me as trash. I cleaned it up, sanded the case and then flame polished it back to something near presentable and then rebuilt it with all the latest parts. It pains me to say that it not only breaths better than my other G250s but also better than my G260s and this 156. Since all the magic is in the air tube assembly I think I need to just pull it and insert it into one of my prettier G250s . And it ain't got no stinking sleeve on it either!
I haven’t been able to find anything not even a drawing. Scubapro rep is trying to dig up info on the one I have, it has a very strange serial number.