Thanks Max and Norm.

I think trying the later boss would be the best bet. I also have a 4 Blade non mulch/catch boss off a PT Statesman in the garage but not sure I want to strip the Statesman yet.

The blades on mine have been mounted below the plate, which is strange, but it was a garage sale find, and who knows what was done to it before I rescued it.

Gave it another run yesterday and the old 125 runs really well. A little underpowered in the really thick buffalo/kikuyu I have in my back yard, but a fresh set of blades will probably help cut. It's never going to be my regular mower, but I've had some issues with my Commando and have it getting serviced at the moment and the lawn doesn't stop growing in this Sydney weather.