set knives on old Geetech (Sunhill) spiral cutterhead

Ruth you didn't get a knife setting tool with the jointer? I have one of their 8" models with straight knives that I bought from them about 20 years ago and mine came with one.

I normally just use a flat hardwood board pressed down on my outfeed table and let the knife springs push the knife up to the bottom of the board to set mine but I don't know if that would work with spiral ones. As far as knives, they are usually outsourced and not proprietary. There are a number of companies that specialize in planer and jointer blades, you just need to google it and see if they have them or contact them withj the specs of the ones you have and see what they have to say about them.

You can touch up your own blades with a jig like the one from Derek Willis in this thread. (I think it was post 12 but can't remember already). https://www.routerforums.com/tools-woodworking/27504-best-bench-top-thickness-planer-2.html