Sacrilege?

OK, I am not a SunTour expert. But I am holding what appears to be an Alpha-5000 (photo from Velobase below) in what looks to be pretty good shape. I want to breakout down, and the upper pulley is not playing nice. There is a protrusion on the take-up spring housing to engage a stop -- that's fine. But the placement of the upper pulley precludes the pulley mounting bolt having its head on the DS or it would get in the way. Thus the upper bolt, and only the upper bolt, has its head on the NDS. And, presumably to ensure that head does not hit the spokes(?), this bolt has a very shallow head. And it is seized. Despite PB Blaster. Due to most sockets having a little recess so the face of the socket does not lie flat against a bolt's mounting surface, the sockets do not engage the flats (oh, 9mm by the way) adequately to break it loose. I have nice open end wrenches, but I am starting to round off the wrench flats. Not happy; I cannot re-grease or replace the pulley. I've considered Dremelling through the center of the pulley and seeing if I could grip the remains of the bolt in Vice-Grips - -but then I'd have fun trying to source a replacement bolt. I am also considering taking a 9mm 6-point socket to a bench grinder to make its engagement surface 100% flat and get another fraction of a millimeter contacting the bolt head.

One presumes that the location of the pulley is geometrically "perfect" but I am kinda seeing a design compromise that makes service so close to impossible.