Glad I'm not the only one!
I heard through the grapevine that ole BigBlockFiero actually had a jig he used to alter his snowmobile belts using a router. I've contacted him to see if he had some tips and tricks; waiting to hear back.
I'm also thinking of contacting Gates directly to see if they have other options with which I'm not already familiar.
Things are actually looking better for me since my custom setup uses a ~35" belt. It looks like one of the 3/4" belts which is available will actually be about right for me, but I will likely have to fabricate a custom pulley in which to install my clutch pulley guts.