As widlely discussed in other Threads, the temp control of the Danfoss BD-35 compressor-based refrigerators is much better (especially above 90F ambient, where the old Norcold can't keep things cold enough).
The TM compartment for the Norcold is more than tall enough for this fridge. (You might need to add a piece of trim to fill in a horizontal "empty hole" of about 1/2", below the stereo slot.) The existing compartment is also more than sufficient for depth (you will end up with about 5/8" unused and un-needed, depth-wise).
But the Norcold compartment width is a bit too narrow. The problem occurs on the small pieces of framing. The wood-look panels don't need to be moved, and the frame pieces don't need to be replaced - but they must be trimmed.
This refrigerator will not "slide" into place until you widen the compartment at those trim boards. (Looking towards the compartment interior from the front fridge door location, you have 4 boards going away from you as corner pieces, plus two "sides" at the very front).
The right way to trim this is from the front, after removing the Norcold but before bringing in the TruckFridge. See other Threads about removing the 3-way propane connector and replacing the 3-way with a simple 1/4" propane pipe union.
With those two jobs done, you simply pull in the new fridge through the front door , shove it back and plug it in, and maybe make it look extra pretty.