Oh dear, a bit of bad news. They're not actually vases - they're gin decanters with missing teak stoppers. I was just looking through some of my information to see if I could pin down that c.1960 to something a little more specific, and I came across the pattern 7648 gin decanter.
The images I have of it aren't mine, so I can't really post them (they were culled from eBay for my own reference), but the stoppers are fairly plain tapering cylinders of teak.