Couldn't tell whether this was a binding or a shelving question/peeve. So
here goes the binding view.  I have bound volume 19 as an  incomplete volume
with a note on the cover of issue 3 and on the inside back cover:"No.2 is
bound separately." Since we bind the title in black, I decided to bind no.
2 in orange. Granted it may stick out like a sore thumb, but users can't miss
it.
Or you may try to bind issue no. 1 separately, pambound issue no.2, then bind
the rest of the volume together and treat it as a split volume. Or you may
bind all three sections separately.
You also may want to take note, that this"no.2"  issue had to be sent back
to the Bindery for "repairs" due to damage during shipping, a total wrinkle
mess.
Linda Oetter-Ayres    "otterears"
Bindery Technician
HSLIC
University of Washington