Ok. You asked for it.
I started by using a 1º spotmeter to read the brightest part of the scene, which is the lit mantle on the gas lamp. Then I measured the darkest part, which was the corner between the floor next to the fire and the side of the desk.
Take those two measurements and find the difference between them. In this case, that gave me 14 stops.
I know that I can scan Fuji Acros 100 film, which has 10 stops range, and get detail in both highlights and shadows, so I now know that I have to compress the range by over-exposing by 4 stops, placing the darkest shadows on zone 3 and then I had to under-develop the film by a matching factor.
That then gives me a perfectly exposed TIFF file that I can the “dodge and burn” to tune the tonality and contrast.