Hi David,
Another different branding...
I managed to score a few sets a little while back as all my blade carriers are First gen and only use this style.
The main drawback with this setup is there are other parts that wear and need replacing and dont come in this kit.
Since I use this style regularly, I bought brass tubing for re sleeving and steel tube for the bolt bushing. I just press the old bushes out and cut new ones to length. Once this is done its just as easy, if not easier to change than the later style blades.
The bolt and blade assy lock down on the internal steel bush and hold the assy tight, while still allowing the blades to move in the carrier housing. They unlike later blade styles need to be well lubricated as they are still metal on metal and dont like debris and dust.
One of my sets is titled Victa blade set, but is also made by another am company. I guess it shows there was just as much variety in AM parts as there is today.