First, Crawley's Amateur Photographer article 13 Sept 08 states:
Sodium L-Ascorbate 1.3g
ADD TO 1000 ML OF A, DILUTED 1:9"
There are some good deals on spectacles these days for those who missed it.
Second,from the old safety data sheet I have ,FX-50,(which IIRC was diluted 1+1+8) would have had about 4 times as much of both potassium carbonate and sodium sulfite as FX-55,but there is no mention of what was the primary developing agent and no mention of bicarbonate so to make a comparison it would be necessary to guess both the primary developing agent and buffer,if any, in FX-50.