Sandy,
Actually I was more interested in an approximate comparison of sulfite and ascorbate at this stage and as you say the EI measurement requires tight controls and only an approximate idea was obtained.I keep a roll of Delta 100 exposed to the same scene,average metering, sun/shade,EI 32 to 125 at 1/3 stop intervals,compare different developers using a loupe on the shadow detail against a light.I get about EI 80 for D76 1:1, the clone gave about EI 125 but was overdeveloped.
Mainly it's interesting the sulfite and ascorbate are both superadditive with metol but it's not known if in the same way.