Just noticed that several websites carry this particular discussion; how embarrassing......
The 2475 I have in my film freezer has to be exposed at EI 200 to get through the base fog, and you have a rather compressed density range on the film.
2475 was named recording film because its principal use was to record oscilloscope traces of fast events or in high-speed motion picture recording. The usual developer was either D-19 for hand processing, or Kodak Versamat automatic processing for long lengths.
Here are two images I made in 1985 during the last apparition of Halley's comet. These are about 45 sec. unguided exposures made with f/1.7 50mm lens and processed in D-19 (2475, Halley-1) and D-76 (Tri-X, Halley-2), if I recall correctly. Both images are almost full-frame, viz. scans of about 80% of the 35mm frame.
The exposures were made on a moonless night with a clear and cold New Mexico sky and no exterior lights to interfere by brightening the sky.
I believe the 2475 was about ten years out of date at that time and had been kept frozen until use. I post these here just to add interest to the discussion.
The only reason I would use this film would be for astronomical photography, especially for something this old, to get over the base fog.
Or just use your paper developer and fixer in a tray in the dark. You are just testing to develop the fog, so it is not that critical in terms of what developer you use or for how long.