Replacement gear for Tidmouth Shed turntable UK

So, I've started trying to open my copy to look inside it and see what/where the problems are. However, there are seven removable tiles and three moulded ones holding the platform itself at the top, and I only managed to unscrew six of them (the seventh might have a stripped screw; I tried four different screwdrivers and none of them engaged with it). I also opened the large panel under the lever and caught a glimpse of another screw that 'seems to' hold the platform as well (like on the manual turntables). It seemed irrelevant to me, though, so I just put the panel back on. Did you have to unscrew it to remove the platform on yours? I should point out that it clanks a bit more quietly when turning clockwise, but strains when going counterclockwise like it does indeed have (a) cracked gear/s. I don't know for sure since I can't (fully) open it anyway. Even after looking under the lever panel and reinserting the arm, the stop/go tabs still fail to retract all the way (if at all). Good thing the track lock feature still works in all directions. At the moment, I'll just have to leave it as is until I could open that screw.