Hello,
here is a formulation for Rodinal concentrate which goes back to the formula of Agfa which was discovered by allied troups after WW2:

Solution 1.) To 650 ml potassiumsulfite-solution 45 % (e.g. from BASF) add 55 g p-aminophenol (free base). It does not dissolve.
Solution 2.) 200 ml deion. water + 40 g EDTANa4 + 42 g potassiumhydroxide (caution, gets hot!) + 15 g potassiumbromide
After all components are dissolved, add to solution 1.) and fill up with deion. water to 1000 ml.

In the original formula there was no EDTANa4 and a special antifog (anthraquinonetriazole) which is no longer available; therefore KBr is added.