The 4th Season (Canadian spin-off show's) Main Theme was originally planned to be included on Airwolf Extended Themes
CD1 (even a mock-up version exists).
However since the ORIGINAL version was released on Amazon (Buy their Audio CD here: https://amzn.to/2w7e43g
or individual themes from here: https://amzn.to/2w786iM
or the Airwolf Season 4 SHORT Main Theme from here: https://amzn.to/2w7lKlW
) we decided it didn't make much commercial sense to try to replicate it, as at the end of the day fans will choose the original over the replica-cover version.
This is a lesson learned from the Jean Michel Jarre "cover scene" where our orchestrator & Associate Producer on CD1 Jan Michael Szulew was very active at one point in the past.
Another thing is that this project is done by both Jan and Mark in their spare time, of which they don't have as much as they would like to. Not having to do S4 version, which is very different, is a big time-saver for the project. Also, as you might have noticed we are generally not
fans of the 4th Season and I guess wouldn't have the heart to do it as faithfully as the rest of the work on the album.