I've not seen any of Galland's Emils marked with a red leg. I've seen most of them include a small red stripe on the underbelly aft NEAR the rear leg, though I don't know if that's the same notation you're referring to. Seems some aircraft had the red band and some a black band in the same location. As for the Mickey Mouse, on his E-3 he seems to have had a red griffon like creature on both sides of the fuselage. On his E-4 he had a characterized mickey mouse (holding a hatchet, a pistol and smoking a cigar) on both sides of the fuselage (an actual photo in Squadron's BF 109 in Action book shows the marking on the Port side with Galland disembarking the aircraft, stogie between his lips). I'm presently using a Tamiya kit to build his E-4, and almost finished. This is W. No. 5819, the rear leg in my references seems to be RLM 65 (hellblau) and as previously mentioned, there is a red stripe on the belly between the stabilizer struts. The markings are bar + pointed bar chevron, from aft forward. My decal sheet (Techmod) shows a number of references for the basis of the markings. Not that they're correct, but I trust them to be somewhat historically accurate, at least as much as anyone is going to know. This all said, I'd not recommend the Techmod decal sheet to anyone unless you love frustration.
Any other questions, and I may be able to help, so feel free to ask, if I can't answer I'll say so.
Hope it helps.