The concentrate you make up yourself. You can cut the KBr further to 0.5g

Ilford PQ Developer (un-numbered formula published in the 50's PQ Version of ID-20)

Phenidone . . . . . . . . . . . . . . . . . 0.5 g
Sodium Sulphite (anh) . . . . . . . . 50 g
Hydroquinone . . . . . . . . . . . . . . 12 g
Sodium Carbonate . . . . . . . . . . . 60 g
Potassium Bromide . . . . . . . . . . 2 g
Water to . . . . . . . . . . . . . . . . 1 litre

Use 1+3 Develop 1 - 2 mins 20C

Neutral/Cold tones: Add 5ml Benzotriazole solution (1%) to each litre of working solution. (Becomes ID-62) To increase the Cold tone further add further Benzotriazole in 5ml increments.

Warm tone: Add 7.5 ml Potassium Bromide 1% solution to each litre of working solution. To increase the Warm tone add further Potassium Bromide to suit.

This Developer formula is identical to Forte FD-203 which is recommended for Forte Polygrade papers, including Poly-warm tone. (No Benzotriazole)

Ian