John,
I thought you had a 120B ? Maybe both ? Good on you.
I have had the tanks changed on my 44, the gauges are re-calibrated...i.e. what it says is what you get. It's about 10 litres less. Surprisingly, that 10 minutes makes a difference, when you are used to a certain amount of range.
Arrrj
PS - sorry, can't "read" any of that old measuring system !