[GreenKeys] Can Anyone remember this TU/Modem?

[Jim Haynes]

Well I sure wish I could find the publication, because I was not
previously aware of a ham design with a stop pulse inserter.  I've
searched the QST (including Ham Radio) index for all of the 1960s,
and CQ for 1962-1968 without finding it.  I haven't yet searched
RTTY.  I have a complete set through 1966, and then my collection
is spotty.  Where else might it have been published?