agreed, thanks for all the effort.
I think with "D-76 Eco" vs "D-76 Classic" things have been answered pretty extensively in it respective thread:
the Eco version is more economically friendly at the cost of a shorter shelf life.
On the HC-110, the classic syrup states on the bottle "Extra-long shelf live", but not how long exactly. the newer fluid version states 2 years for the concentrate and 6 months for the working strength.
Interestingly, both list Dilution B as 1+31, so the concentration of the active chemicals seems to be the same, and the price is very similar too too (the syrup being 8% more expensive)