on my desk - just measured it and it's showing 26mm OD - if you can find the spec on the 79090 dial's OD, that's one parameter but i suspect it is 26mm as that's a common size
as to the dial's feat - i've saved notes from dials i've had off, and on the 9401 & 9411 dials, the dial feet are located at 11 minutes and 41 minutes. Have no idea where they are on the 2824 mvmt used in the 79090 but it's such a common mvmt, it shouldn't be hard to find out