Someone asked me to try the Kunz blade in the Stanley #80. It fits fine and the blade thickness is about the same as Record and Stanley types too. In my view a scraper blade should not be less than 1mm otherwise they tend to flex. If you need to replace a blade consider buying a card scraper set made by Veritas or indeed any card scraper 1mm or thicker. The Veritas set has one scraper 1mm thick that yields two cabinet scraper blades when cut in half and this fits any #80 scraper. The set costs under £10 for four scrapers and the other three scrapers in the set make better card scrapers than the thicker one. This makes it good value.
I used the Kunz blade in the Stanley for a while and it cut as well as any other and the edge retention was good so far, but a real test will take longer. I will finish out some sapele parts today and if it lasts through that then the steel is good. So far I am happy and the green is growing on me.