you cant strip powder coating with oven cleaner or aircraft stiper as its baked into the metal.
best bet is to take it to a machine shop and have it sand blasted with glass bead, nothing of higher grit than that or it with pit and destroy the metal. dont know how much they'll charge you though
Sears sells a mini sand blaster which works well, but your gunna have to have a air compressor to run it. the glass bead is blue in tint and runs about 28 bucks for 50lbs.
also make sure you press those bearings out before you start sand blasting unless you have about 50 bucks to replace them