I had a similar experience with the crayford focuser on my SW 72ED & took one of the bearings into allied bearings here in Cairns.
I took an intact bearing in to be measured & I was able to purchase replacements although they were fractionally wider but, importantly, same diameter.
In the end I purchased 4 & replaced all the bearings... job done...
Not sure if you have an Allied Bearings in Vic however, I'm sure you'd have a bearing business of some sort near where you are..
A quick google turned up Metro Bearings in Clayton South, Vic maybe give them a try...
https://metrobearings.com.au/
Cheers