Hello
This is a bit of a mix up . It is a Suffolk Punch 17 I believe,and a 1F engine was the first of the 98 cc iron version which has extra cylinder head bolts. Clutch cable is an add on. As you say most had the fuel tank on the engine but I cant see the holes for fixing. The fuel tank fitted I don't recognise at all. They were sound mowers- also made as Punch Professional with 10 blade reel, shaver bottom blade and steel front roll.
Think the exhaust is a Briggs type copy and I would date this as sometime between 1967 and 1976
