These days I am more surprised to find that a manuscript is not online than to find it is. Chicago has lots of good stuff including highres images of Minuscule 2412. Most of the pages have a white block for the main text, while the wide margins are darkish yellow. If I look long enough at the outside margins, I could nearly convince myself that we have the remains of letters here (lower margin, image 8, also some of the previous pages):
Even if the manuscript is a palimpsest (and I have heavy doubts myself), there won't be enough left to reconstruct a text and therefore be pretty useless information. I can think of some options that could explain these marks ranging from patterns within the actual parchment to marks made in the preparation of the material, or even offprints of some other page made in the process of binding. I am not sure if it is worth anyone's time, actually. It is probably as useful as looking at marginal dots.