Every Cherokee-D I have built from an Estes kit has had the PNC-55AC and 18"tube.
They were all pink skill-level packaging. I have built at least 6.
I suspect the change to full length BT-55 occurred at the same time as the switch to the plastic nose cone and skill-level packaging. Somewhere in the 1973 timeframe.
The only ones I have built with balsa cones were PDR and Semroc clones.

__________________
When in doubt, WHACK the GAS and DITCH the brake !!!

Yes, there is such a thing as NORMAL, if you have to ask what is "NORMAL" , you probably aren't !
Failure may not be an OPTION, but it is ALWAYS a POSSIBILITY.
ALL systems are GO for MAYHEM, CHAOS, TURMOIL, FIASCOS, and HAVOC !