Many times some folk paint the sides of tube track to hide surface rust. If you want to remove the paint, use lots of, "elbow grease". You can use a green pad like you use to clean your track. I would suggest to leave it.
For your red lantern, I would let the folks on the Tinplate Forum know. Lastly, if that doesn't work place a listing in the WTB Forum explaining your need and that you're not able to buy one. I already checked my parts drawer for a lantern, however, that space was empty.
Thank you so much for the advice and trying to look for one!