It is a Fowlers Vacola No 65 preserving jar.
I have preserved a few batches of fruit in Nos 20 and 31. The No. 65 would be great for preserving whole peaches I guess.
Thought I should add a photo to show the scale of the jar.
That is a 20c coin standing next to No. 20 jar of this year's nectarines.
One site on the web says Fowlers stopped making this size in 1975. I wonder how long it had been sitting in the back of someone's pantry before the final clean out occurred?