The Replacement Tripod Foot with Retractable Metal Spike from Manfrotto is a sturdy rubber tripod foot with a retractable metal spike for use on all types of surface and terrain. It is compatible with the following Manfrotto tripods: 3221G, 028B, 055NAT, 055NAT2, 055SSB, 058, 058B, 344B.
It is not the same as the original, but it worked.
One of the feet on my wilderness tripod was lost during an aurora/ISS shoot in the cold and I only noticed after I left the site. This is nearly identical to the original foot and was easy to install, I recommend using a sturdy mallet or a hammer in a pinch to force it in to place. It fit snugly to the same spots as the other two feet and wasn't difficult to install.