I wouldnt be a happy chappy either.Yes its a model 5 series 2.Predicta extensions deleted.Your enigne is definately an IAAD..... And is correct for the model 5 series,just of a later model as blumbly suggests.More likely a 3.Hope you didnt pay much.This version of the 5 is not very appealing to me personally,and holds no collector status.BUT each to their own,Im not here to bag out your choice of mower,It will restore nicely.If you are keen on the specials and want something a little rarer,lower nos or more iconic,go for the earlier models.Model 4 Predicta,STD,model 5 series 1 the first TRUE special nos should run from 110,00 to 128,000 Then around 200,000 to 300,000 for the true model 5. If the starter with the round knob has the lock nut on top.relist it on ebay and probably cover what you payed for the mower?.