What you have there is a Model 33 which was the precursor to the Model 45 so this makes it a 1960's issue as it's not the Lawn King variety. The Model 33 was a 16 inch wide cut machine. This one no longer has its original engine as its been replaced with a 1979 Briggs and Stratton 3 Hp engine.
Cheers, BB.
I live a 24 Hour lifestyle, but every now and again I seem to fall asleep, well at least that's what my wife tells me.