Inside and outside are 2 entirely different beast in terms of wood care and how it's finished. If wood is treated and finished properly, wood does just fine outdoors with maintenance every 5 or so years. And since this isn't an outdoor keyboard, I don't think I'll need to worry about that. The finish I use and the way my wood is prep should be just fine for indoor use
I'm straight up confused by the overall meaning of your post
Sorry. I live here in Perth and currently it's nearly always a hot climate altering between high humidity and dry heat during the year. Hence anything related to wood just either dries out or deforms in shape.
Even though I have air-conditioning in every room it doesn't run 24/7 through out the year. Hence when I'm at work for two weeks the house is locked up tight. Hence the temps in the summer hover around 110F (your temps). When I arrive home most of my wood furniture is deformed and anything wood related cracked (even a chess case I had for years is now ruined).
But everything made from Steel, Heavy gauge plastic is in perfect condition. Hence only through personal experience I know what it's like to own wood objects because it all to frequently gets ruined or I just can't be bothered to oil it on a consistent basis. I use to oil everything once a year but now it has to be done at least three times a year.
Heat is a powerful deformer hence if you are serious about a wood case then it will need to have extremely large recesses and material around the keys. Even then it's no certainty that it will hold it's shape over long term.
I only suggested "Recycled Plastic" as it is a viable alternative to wood and can be finished into a durable key-board case. Dare I say it, it could even weigh more than an IBM.
But this is only my suggestion so please don't get angry about it, suggestions are made to be ignored, especially when it's from me........