I don't even understand how the masking can be the cause of the delay. I don't believe it should be that complicated. Where I could see the problem is with fixing the palette so that only the colors that are needed are included (like I mentioned earlier, the old wood colors should have be updated). If no one was going to be a perfectionist and just ran a final unedited image through TilesetPal, the set should've been finshed sometime last week.

But enough of me being impatient. I'm no longer in any position to help anymore.