Two Prunefaces
The cast is listed in order of appearance in the movie and on IMDB. Pruneface is listed before Mumbles which would mean he appears in the scene Lips is taken from the Club Ritz or in the warehouse scene right afterwards.
There is a gangster in both scenes that has a very scarred face (he is next to Flattop when Lips is getting the cement bath). Was that Pruneface? I realize the real Pruneface appears later but that cop sure had pretty scarred up face that resembled Pruneface.