So I just stumbled on your video. I have a 2003 Coleman Niagara and when I take out the Cassette to empty, there is always that little leak from the top flange, I started looking at a replacement and those are not cheap. This is the perfect option you have demonstrated!
In the earlier video we learned to leave the aperture open - which really cheesed me off as I left my spare toilet in the outside garage where the temperature is now -10C. I won't do that again.
Brilliant video, thank you. I have just had a fortnight in France with a flip-flop full of my families urine every other day as I carried the cassette to the loo. I shall be doing this repair on the weekend. Excellent tuition Sir, bravo.👍