Oh, I may have bent my castings apart a tiny bit too... saved me a lot of filing/sanding.
Whoa, I wouldn't try that! The rudder castings are cast aluminum, and casting is more likely to break than bend! I bought a used pair of the original EPO's, which needed to be completely reconditioned (they were badly sun damaged, glass exposed, and then lazily painted over with a spray can). I couldn't tell until after I started coating them in epoxy... then all of the sudden I could see the imprint of the original decal
I too had to file down my castings. I spent days filing, and ended up taking a bit of material off the rudders with a sander too. I may have built the heads up too much. I can't remember exactly, but I think I rolled on 3 or 4 coats of epoxy, followed by a lot of sanding between coats to get them smooth. Not a process I much want to repeat! The EPO's are still a pretty tight fit, but it gives me smooth response out of my rudders once I upgraded the rest of the rudder system to remove all the slop. Just don't force them, those lower castings have a known weak spot on the side and are prone to breaking, and they aren't in production any more!