I was able to double the frame rate by reducing the number of vertices in the drawing object down to 24000. I also added a little bit of dark green fog to get it to look somewhat similar to the original.

If you want to try version 0.05, you can download it here.

https://schmidt-workshops.itch.io/the-horror-in-the-museum

I'm wondering if it doubles the frame rate for you too, or maybe it will improve more than that...