No, he's still around!
Warthog: I wondered too.... since this would be for the 8.3 CTA engine, and yes, it's there: TM9-2320-272-10, page 0034, Figure 7.
Soooo... once again: RTFM!!!
G.
Edit: The TM mentioned above is from 2012. The one in our own library is an older version, from 2004. In that one, that "missing" plug can be found... in Chapter 2, Section IV: "Operation Under Unusual Conditions/ Deep Water Fording", pages 2-220 to 2-222.