I received my Flo 60/90s!
When I put on the front, the brake could not open wide enough to allow the wheel to spin without dragging. I could just get it centered and it would be fine, but any nudge and it would be touching again. Once I get new brake pads, there would be no chance.
I removed the concave spacer that sits between the brake arm and the pad holder and put it on the other side of the holder, with the concave side facing out:
That gave me about 2mm per side and it fits perfectly.
Is this fine? My concern is that the concave washer/spacer seats the flat brake arm flush with the rounded pad holder and now I do not have that assurance.