[Arran]

I have a couple of questions regarding the entire process sequence on a Philco cabinet. After stripping the cabinet I have base stain on the veneer providing color and on the trim no color. Most of the filler techniques suggest staining 1st, but if there is already dark tone such as the veneer on your 42-761EZ , what makes sense?

No stain on the veneer, the only area I would use a stain, or rather a wood dye, is on the grainless solid wood parts. The stain they sell at the hardware store is crap, to be frank, it's a muddy pigment suspended in oil or some other solvent, it obscures the grain in the veneered panels and doesn't penetrate the solid wood parts. Mixing a dye or some sort of pigment into the grain filler is sometimes necessary if the filler is light in colour to start with, or you are using plaster for grain filler which is white.
Regards
Arran