: Ratio 5:1 weight and volume
: (207 hardener which more of us use is 3:1 volume 3.5:1 weight)

Good grief can't you find something with a 2:1 ratio? Clever of you to spend some time to investigate this, it will pay off given that you decided on this horrible ratio elixer. My methods are much more low tech. I use plastic cups where I put 2 marks on the inside with a blue marker, and 2 with a red marker. For smaller amounts I use bottlecaps of different sizes. Anything that does not fit in these constraints is eyeballed. 2:1 is quite forgiving, I found.

By the way the real question is, what are you building??

Henk