Hi gravelman, I'm glad to see that you got the reel out ok, sorry to hear that the reel is unserviceable.
Mate,the thing to remember here is that you've purchased a piece of precision engineering, some parts of it's operation requiring close tolerances.The machine will require regular maintenance and replacement parts will tend to be expensive, but that is the nature of the beast.
To have a worn reel within 3-5mm of the separating discs means that it has done a lot of work in it's time, and has been sharpened many times. My guess is that the bottom knife-blade will be worn as well, and probably in need of replacement.
The model 430, not being a very popular machine, I very much doubt that someone will have a spare reel lying around...
Keith at TMS, is one person that has a heap of used spares for most Scott Bonnar models and has a reel to suit your for $137 delivered, which, in my opinion, is a very fair price.
My thoughts would be to get Keith to spin-grind (sharpen) the used reel for you (if it hasn't been already)and depending on the condition of your bed-knife, supply a new one, ground and fitted to your knife-blade holder.
You would have to send him the blade holder complete with the existing blade...(he has the expertise to remove it) The reel bearings may need replacement as well. For correct reel to bed-knife alignment, the bearings have to be in perfect condition.

You could then put it back together, carry out the alignment, check and adjust your belt tensions, and then you're ready to go, with many hours of mowing pleasure!

Just remember that these machines were approximately $1700 when new, so even with the extra expense, you've still got a cylinder mower at a great price.