Shower replacement detail

[tomtheelder2020]

Old shower demo down to the studs and replaced with new tile. The contractor is done except for installing the shower door. A small detail I have to resolve is that molding around the ceiling is about an inch short of the new tile (see photos). I will look for a piece that will match this 1951 molding but I am not hopeful. My wife would like to removed the molding on all 4 sides but, particularly if the molding is hiding a gap between ceiling and wall sheetrock, that could turn into a lot of work.
Even if I find the molding, I would have to either bevel or round the end for a smoother transition. I am considering trying to simulate that by filling the area with joint compound, then "carving" it (mostly by sanding) to match the molding. However, right at the edge of the shower is going to be a high humidity area. Does anyone have an idea for a material that would carve similarly to the joint compound but be less susceptible to moisture? Any other ideas for filling this gap?

 

[soparklion11]

I could see throwing some DW compound up there and going over the existing molding with a drywall knife to recreate the pattern... you've got nothing to lose except a bit of time and a bit of compound. If you seal it and paint it, the moisture won't be an issue. Plastic wood or a wood filler might be a better material... someone here will surely correct me, but I think that you could make that 3/4" x 1" repair on non-structural molding either way.