Hi mattbutton and CyberJack,
Well CJ has pretty much answered most of your questions, but I'll try and fill in a few of the gaps for you.
As far as a replacement catcher is concerned CJ is spot on there as second hand catchers in good nick just don't show up, basically the story would be, where's the machine it belongs to ?
You could get a new catcher made up in Brisbane by "SB Obsession" on this forum as his father in law Denis makes them and does a pretty damn good job if I don't say so myself. Being in Brissy the freight wouldn't be an issue for you as it is for all us Southerners.
Replacement power plant, depending on your budget, I would go for an OHV as CJ suggested and if the budget is thin then a Chonda (Chinese copy Honda) will do the job rather nicely.
As far as repairing the split in the chaincase is concerned, and this depends very much on your skills and equipment accessibility, but it can be easily zapped up with a MIG welder or if you have OXY available you could carefully braze it up using the brass to add to the overall thickness in the area of the lost metal due to the chain wearing it away.
Again as CJ has suggested could you please take some good close up photos of the drive train side (LH) of the mower, the tops of the rails where the engine is secured to and also the reel and bed knife assemblies. From there on we can give you a much better idea as to which way to go.
Cheers,
BB
