mmmmkay I knew I wasn't completely crazy. The mag float I have is only good on aquariums up to 3/8 thick, not 3/4, and the version that replaces it, the flipper (
http://flippercleaner.com/) is only good up to 3/8 as well.
I see that the algae free does have scrapers that work on tanks 5/8" to 3/4" thick, but their handles don't work with the look of my tank. In a worst case scenario I could paint the handle of the algae free unit white, but is there any other brand that comes razor-capable that can handle thicker glass?