Hi,
this is my favorite paper developer, and I find it amazing for its longevity and capacity.I've decided to share the recipe, hope this is the right place.

The developer is well buffered and develops with a neutral tone:
П-80
water - 750ml
sodium sulfite, anh 20gr
Hydroquinone 3,5gr
Sodium Carbonate, anh 20gr
Phenidone 0,15gr
Sodium Bicarbonate 2,6gr
Potassium Bromide 1,6gr
Add water to 1 liter
I use a 1% solution of phenidone in methyl alcohol, and add 15ml of that, instead.

I've had excellent results with this developer, and I hope someone else will, as well.
Nikola