Many older HP/Agilent instrument share a similar feet design. There are at least two different types though: One with a metal part to prop up the instrument and one without it that can be used on all four corners. The feet can be detached from the instrument, e. g. for use in 19″ racks. This also means they got thrown away too often, so that many used instruments come without them. For some time they were available on ebay at a reasonable price.
Unfortunately, this doesn’t seem to be the case anymore. So I searched for a simple 3d printed alternative (without the metal part of course). Sure enough, CatalinaWOW @eevblog has you covered:
Out of the box (literally, I don’t own a 3d printer…) they work pretty well, however mine seem to be a bit loose – something that likely could be fixed reasonably easy if really required.