Try Paul Farber's Acufine substitute and mix in whatever quantities you like. The citation I have for this is Oct. 1984, Photographic magazine, which may have given it in teaspoons and tablespoons, but I weigh the ingredients in grams and use it in a 5 quart 5x7" tank. It lasts quite a long time (many months), as long as it isn't subject to high heat, and capacity for 5 quarts is about 160 rolls or equivalent, increasing development time by 2% after 80 rolls. Because the heat issue can take you by surprise, you might test a film leader to be sure it hasn't crashed, if you haven't used it for a bit.--
Water (125F)--about 2.5 cups
Phenidone--0.25 g
Sodium sulfite--53.2 g
Hydroquinone--4.5 g
Borax--2.5 g
Sodium Carbonate--2.25 g
Potassium Bromide--0.8 g
Water to make 1 quart
I'm sure there's a Microphen-like formula out there as well, but this is what I happen to use.
You can also still get real Acufine, Acufine replenisher, and Acu-1 one-shot developer. B&H usually has it.