I heard of the "withdrawn" story but to be honest I don't believe it. I checked Discogs, 10 copies sold over the recent years and currently 3 copies for sale. If the album was really withdrawn shouldn't it be rarer?
However, as you said, there's probably some demand coming from collectors who are into Stones, Small Faces etc.
But, back to one of my initial questions, are there any non-45 tracks on it that justify that demand?