Well, I ordered one from Australia, one from the US. They both "got stuck" in the current troubles, one spent a month in London being send back to Oz (!), the other spent all of April in SFO waiting to be exported.... but the Australian one arrived today!
I'm following your helpful instructions... but I have this extra part (see right hand part in image below), which looks like the back part of the "cassette" which the portcullis ought to be sliding up and down within. I suspect this is the root cause of my problem, because this looks like it should be bonded to the front part of this cassette, so the portcullis would be supported against hits by the ball from the front.
This is just rattling about, serving no purpose. I think I should bond this back to the front part of the cassette. Any opinions? I can use Araldite (epoxy on it I suppose, but maybe I should augment it for strength, maybe wrapping something metalic around the whole thing to hold it together?
--
(Taking the castle front off is easy, and makes access to a lot of that stuff easy.
I think I will need to remove the solenoid assembly as I can't otherwise poke the portcullis back through the slot there.
Oh, no, with a little effort I can get the gate back into place, probably because the back of that cassette is not attached, so I can wiggle the gate up there at an angle. I now have it in place. Time to think about fastening the back of the cassette back in place.).