G'day all,
The 'spider' spacers would help to prevent the blades bending, I'd say.
The across-flats measurement of the hex shaft will determine what blades will fit. Scott Bonnar grooming 'wheels' used 25.4mm [1"] hex, but may be difficult to find now -
NLA example. Golf & Bowling Machinery in Vic would probably be the best bet for those.
One of the blokes in the threads linked below used 27mm hex, but he didn't mention what the OEM machine for that blade/wheel was.
Setting the 33 up as a groomer would be cheaper than acquiring and setting up an SB45, if it's anything like a reasonable price.
If you haven't found them yet, here are a couple of threads where ODK members made, or had made, groomer reels for SB45's.
https://www.outdoorking-forum.com.au/forum/ubbthreads.php?ubb=showflat&Number=22926https://www.outdoorking-forum.com.au/forum/ubbthreads.php/topics/60344/1.html