The defining characteristic of a Balanced Adjustable 156 is the G250 size exhaust valve. A Balanced Adjustable is not a 156 unless it has this feature. There are at least a few 156 with G250 exhaust valve but no CE stamp.Not all 156 have a CE stamp but all large exhaust valve 156 that I have seen have the CE stamp.
All Balanced Adjustable with 109 size exhaust valve are always either 150 or 152, but of course nobody uses the term 150 so referring to them simply as Balanced Adjustable makes sense and keeps things straight.
It's a minor thing that does not really matter, except when creating confusion for those searching for the real 156. But once the difference is understood, it comes to mind every time a "156" is listed on ebay or discussed in a thread.
The lack of information about the real 156 is what prompted me to start this thread over 4 years ago, when I was searching for one and trying to sort thru the mixed and conflicting information about which Balanced Adjustables would have the G250 exhaust valve. I had no idea what to look for. Thanks to everyone who has contributed to this thread!