There are published reversal baths. Here's one from the 1988 BJP Annual

Reversal bath (pH: 5.8 +/- 0.1)

Propionic acid 12m1
Stannous chloridc 1.65g
p-Aminophenol 0.5g
Sodium hydroxide 4.8g
BDH Calcium Complexing Agent No 4 5ml
Water to 1000ml

Notes:
1 The very mall quantity of p-Aminophenol can best be measured by making a 0.1% solution (1g/1000ml)in 1% (10ml/1000ml) of propionic acid. This solution does not keep well can should he discarded after a week or so.

2 If the solution, particularly when made up as a 20x concentrate, does not clear on adding the calcium complexing agent in the above quantity a little more should be added slowly until it does.


But don't try Hogg Laboratory Supplies (as suggested) for your chemicals they closed a few years ago. They ceased selling Photochemicals sometime before that. I went in to get a new price list, was told they'd stopped selling them so when I asked what had happened to the stock they found Mike Hogg who said make me an offer. I had their entire stock for almost nothing. Loads of Pyro, Amidol, CD-2,3 & 4 etc, Pinacryptol Yellow. wetting agents restariners the list was long.