That looks to have very similar chute flap to the Rover Princess my Dad had when I was a kid. The flap has no lip, only closes to approx 45� and has a lever to lift it on one side.
Unfortunately the catcher we had was made of a blue plastic that was dreadfully unstable. Within a few years it had started deteriorating, and the deterioration was brittleness and crazing of the plastic. So bad, when we tried to tape it back together, the catcher simply started crumbling. Now I actually saw one at the tip last week and was very surprised it was still here, but it was showing the crazing deterioration, bad memories so I declined to collect it.
Furthermore the catcher design was flawed. There was not enough venting I think, it used to clog (with the vents at the top rear sides and shrouded from the outside so you had to access them from inside the dirty catcher) and have to be cleaned, same with the discharge chute. But worst was the lack of the lip on the chute lid to hook onto the catcher. So the catcher simply hooked on by the 2 hooks at the top and rested in position against the frame at the bottom with a little lip inside the chute. This, coupled with a very low catcher base meant turning the mower or uneven surfaces was fraught: you couldn't tilt the mower more than a fraction to turn and/or bumping the bottom of the catcher would result in it detatching from the mower. And if their was grass in the way when mounting (either frsh or clippings stuck to the frame) it might just self-detach anyway. Doesn't sound that bad until you remember the next things along 2 feet behind are your 2 feet!
