First query after vacation

[sagehen]

>I've heard of the intrusive R, but an intrusive S?
  >Kathleen E. Miller
 ~~~~~~~~~~
I hear "alls" a lot, and the  other day noticed that someone, in writing
dialogue, spelled it "all's" which made me wonder if could be /all as/: not
that /as/ is needed, but it might somehow feel right to the speaker. Maybe
/s/  is insinuating itself into speech by some such route.
A. Murie