Unless the stars really align for this one, it will be a while before I can post it up though. I get the feeling it will take a few test prints to get everything right. I'm planning to print this using Hatchbox Wood PLA, which I have had good luck with in the past.
I still need to re-test the single lithophane night light, hopefully I can get that one posted well before Christmas.
Update 12/24/2021 - This was completed and works great (also looks pretty good too). I posted this in another blog entry above, but thought I should post here also - the final design is now posted at Instructables (where it got featured in "Workshop" and is entered in their "Anything Goes" contest). It is also uploaded to thingiverse: