I would bet it would bolt in. I had plans to put a 41 Plymouth dash in my 40 before I sold it. Everything looked like it would bolt in.
I haven't owned either one, so no personal experience, BUT, the 41 Mopars tended to be mild facelifts of the 40s, while the 42s tended to be closer to postwar stuff. Yes, the word "tended" is working hard here. I'm talking about door to door dash, cluster to cluster will not work. 1940 1941
First big use of the space age material, Plastic! Looks are in the eye of the beholder, but they have got to be more common.
And the BIGGEST problem....the plastic disintegrates over time. Although I probably won't retain the original dash, I have been toying with the idea of reproducing the existing 40 dash plastic parts using a 3-d printer; they aren't that expensive considering what can done on them. I suppose any 41 dash would have similar issues with the plastic.
I've had good dealings with this place, which is closer to you than I am. I don't have a spare... https://mooresautosalvage.com/about-us/