I came across this cool article in the Lighting Answers series months ago, I have no idea how I found it but it is a great series!

I noticed in this 2006 edition "Dimming Fluorescent T8 Problems", there seems to be a number of possibly black capped F32T8s listed in it!

  Westinghouse for very short time before philips take over.
  Wasinghouse had  made what it called the  Octolume black ender T8 F32s.  L

  Sylvania made blackender T8 F32 little longer than Westinghouse did before switching to Aluminum end
 Caps.  But being early fluorescents
 Most of them got used up.  Cause it was a new lighting system
At time.  So people bought what they need.  That why it so hard
To find and rare and highly sought after.  It going to be tough finding old  stock blackender.   

The close i ever found in 1980s
t8 is those GE trimline partal case.


   

I actually wrote an argumentative essay for English class a few months ago arguing that the Westinghouse Octolumes are the rarest-

I wouldn't be surprised if the first one ever found in the wild is in an abandoned building built around 1982-1985...

I personally have no F32T8s in my collection...