Up for sale is my used 749R triple set. This is a 1:1 swap with the XX9 series. As you likely know, the 749R is/was the only XX9 with an eccentric to allow an offset of 36 mm (OEM) or 30 mm. The latter will make the bike more flick able. By altering the rake (i.e. turning the big (frame) head eccentric) to 23.5 degree you will get superb stability. I am asking 550 Euros. Insured and traceable shipment will be 36 Euros.
The offset is adjustable to either 30 or 36mm AFAIK this will fit all 998 999 1098 1198 and some 748 749 848 given it has adjustable steering angle. Here is a link on another forum of someone who fitted it to a 996 http://www.speedzilla.com/forums/ducati-superbikes/14828-question-about-749r-triple-offset.html
It certainly doesn't fit all 749. Biposto steering stem is much longer. I had ohlins put on my Biposto and had to have a steering stem manufactured as the S and R ones are too short.
Apparently you're right, seems to be if you have a frame without adjustable steering angle ( some 748, some 749 and some 848 ) then this won't fit. They call it an E frame, Econo frame, LOL http://www.ducati.ms/forums/56-superbikes/273297-ducati-749-steering-stem-shaft-length.html However all other bikes with adjustable steering angle it does fit. You learn something new everyday on forums.