T500 transmission gear problems & options

[jabcb]

Some time ago I bought a what-looked-to-be-good spare T500 transmission on eBay. Recently took a close look at it.
Rubbing the tip of a fingernail on 5th gear, I can feel the infamous & typical damage.
4th gear looks fine.

Finding a good T500 transmission looks to be slightly easier than finding hen’s teeth.
I’ve heard of using a GS750 transmission in a GT750, so I was curious about alternatives for a T500. Didn’t find any transmission swap options.

Found a company in the UK that makes racing transmissions & parts. https://novaracing.co.uk/suzuki-t500-st ... ment-gears
Their complete T500 transmission is crazy expensive. But individual gears are reasonably priced.

Does anybody have experience with using a Nova Racing 5th gear set with a stock transmission in a street T500?
The driven gear is an easy swap. How is the 5th drive gear swapped & are there shops that would do it?