I found a set of 4 on ebay of the proper color for my unit (brown or green). And this set includes two of the wire tilt-stands. So happy ending for me.
By the way, for anyone interested, Keysight still manufactures these feet and tilt-stands and you can order new, directly from Keysight. Though I think they only supply gray ones (a dark gray and a light gray).
Cheers