Hi Ian55,
Nice to see your model 45 that seems to be one of the very last that was manufactured at the Adelaide based Thebarton plant before operations moved to Brisbane.
Your machine was made in early 1983 as the engine was assembled in the USA on the 19th of November 1982, thus that engine would've been fitted around 3 months later to a newly made chassis.
As far as removing that glorified gutter bolt that secures the chaincase to the mower I would give it a bit of penetrene and then use a screwdriver as if you are undoing the bolt head and gently tap the end of the screwdriver with a hammer while pushing hard against the screw with an undoing twisting action at the same time. Try not to allow the screwdriver to slip and flare out the slot in the head.
This should work as it has for me everytime.
Cheers,
BB
