Here is the measure I'm talking about. White is over .62, where all the rest are .5 or less (at least of those I measured so far).
And this is what the foot looks like off the machine. This is NOT a White, as I couldn't get that one loose - needs more oil.
This is a very common attachment type of the 1890-1930 machines, and most other than Singer used this. But in the end Singer won out - and the US machines all had side clamp feet -which most have some sort like that today.
There are some older feet that fit right on the presser bar. They are an older style foot, and a lot harder to put on and off - and keep lined up correctly. I have several intersting styles of those.