" I am wondering if there is anything I need to do in terms of pre-mowing season maintenance and as I have never owned a cylinder mower before, things I need to be mindful of/watch out for?"
Also you could check youtube Video for maintenance tips even if it's a different model they are generally the same parts to lubricate and check.
With the catcher ,I've seen someone on the Facebook Scott Bonnar group making and selling new catchers but not cheap from memory .
If you had of asked a few weeks back I saw a good model 40 advertised with catcher sell for $50.
To make a catcher at home it doesn't need to be the exact measurements ,it just needs to work ,if you already know the width of the catcher by looking at the mower you can work out the other diementions by looking at images and using maths to calculate the measurements.It will be close enough.