In one of my "Radio Times: Guide to comedy" it says that season 2 aired 28 episodes and I compared it to the other seasons and it does work out to 120 episodes aired at the original time of release. So, I imagine that the first 4 episodes of series 3 was shown on TV straight after the end of season 2 - this could possibly show that the Kris Kristofferson/Rita Coolidge episode needed to quickly put editing together for it to be shown - hence the re-use of classic already shown clips.