Thanks Blumbly,appreciate the imput...Im Unsure why they changed,maybee it really was a misprint,But why it changed isnt as important as determining the Correct models.

The fact that the image states the use of the Impulse starter as an option for the Model 6 (tank on cowl) as per diagram,to me says that it is actually as the document suggests..A Model 6,Not 9. No other document shows this. I think this is a very important piece of information.

My engine nos all have letters in front irrespective of model. 3 are actually DAB...... So I dont think the answer lies in the Engine numbers. The ones with the numbers only to me would suggest a later engine as this is when the date codes started,so if anyone has a model with this full number sequence please let us see what model it is on. Im now almost certain the the answer lies in the starter types Especially since the model we currently know as 6 (Tank IN cowl) NEVER came with this starter type(impulse).
..Get me?