Sealed Cabinet with 1/4" Input Jacks?

[Jazz P Bass]

Yeah, that 'locking plug' is pretty cool.
Switchcraft : 1/4" Locking Plug and Jack

[Bill Moore]

Never thought about it before this thread. Got a flyer the other day from CE.
Here they are listed for Cliff jacks in the AES catalog.
Seal, for S-H910 and S-H911 Jacks, Cliff UK | Antique Electronic Supply