Threaded up the Gong Show many times. It is an alpha wrap. The tape crosses back over itself around the drum. It was important not to allow the tape to run off the end of the reel as reverse threading it was difficult.
I can tell you that my VPR80 is an omega wrap. The tape does not cross over itself. Beta decks and 3/4 are also omega wraps. The tape does not cross over itself.
The best IVC machine I ever saw was the IVC 9000. It was a 2 inch helical machine with stereo audio and recorded on the super hi-band standard.
It was a slant deck similar to the Ampex AVR3. It was a teleproduction machine with editing. Picture quality (S/N) was better than quad (hi-band).
Unfortunately, it was compatible with nothing else.
A production house here had one. Might be a few left in Hollywood.
If you're looking for video heads, you might contact AheadTek:
http://www.aheadtek.com/