I have 2 engines which I never seen another pictures or prochure. Another engine has a date marked 10 Y 4 Y 23, so I beleive it's made in 1923. I also have hole bike, model 180 1924 and that engine have same sylinder barrels and it's look quite much similar. But whichkind of frame that should have on these -23 engines? Or do somebody have any more info or maybe picture of that model. Normally -23 model of 180 have magneto front of sylinder barrels and -24 it shanged to behind of barrels.