I've always found that a bit of heat will solve most of those baked on issues... typically when I have some cruddy sheet metal parts (think VW bug tins) I'll just pour some gas on them and fire them up. Doesn't get them hot enough to hurt them, but will get them hot enough to cook off any grease or oil that's caked on. Will typically flake right off when cooled. Obviously, this will kill any paint on the part, but if you're going to repaint anyway then it's not an issue. Maybe a propane torch would do the trick. Just a thought...
09 KLR 650, blue... Done the Doo!, Thermo-bobed!, LED driving lights, aux fuse box, HID high beam, gel battery, custom racks, tool tube, de-Californicated it, moved main fuses to side cover, relocated plate, PVC mod, Hurricane mod, bypassed the side stand switch...
RIP - 95 Honda VFR750 (the most vulgar shade of yellow I could find in the book!)