(just scrolling around and decided to do a fly by comment)
So, I'm a Yank, but what does the UK have in the way of glass mason jars used for canning? In the US, the larger containers (32oz/64oz) are molded in such a way that there's measurement markings raised on the outside of the jar.
Any friends/coworkers have older relatives still around? Maybe they've got some canning jars with the measurements sitting in boxes in an attic gathering dust?