I've put Honda CR80 plates in a Costa clutch on my PX200. The ears need a bit of fettling as they are too wide for the basket slots but as they are alloy its an easy job. I have put 3 plates in with the standard vespa top plate with friction material on one side. However it would probably be better if I had removed the friction material from one side of the Honda plate but time didn't allow.
Anyway it performs very well, smooth and consistent and value for money. IIRC £10 for 5 plates.
Serial scooter rider...
VMSC Committed to Scootering for 25 years