Sorry, just re-read your post and you say it is a 111 that you have a problem with. I guess my point still stands though, will the multikey work on earlier 111 models?
It will work for replacing jets on earlier 111T models. IIRC it's no good for anything with 111 & 111B models of any age, and it will fulfill all its intended functions on 111C models.
I’m a bit of a novice on jet replacement on Optimus 111 so naive questions coming up: Is it best to screw in jet with cleaning needle already engaged or screw in with cleaning needle already inserted in jet? Either way what position should valve knob be in - CLEAN? CLOSE? or halfway?