Sorry to hear that you are still having problems with cats and the rooks sound like a nuisance too. The jackdaws and crows here will take whole fat balls if they get the chance!
The cats here don’t even attempt to get into the feeding station anymore, the only drawback being that you can’t see the hogs inside, but I suppose that you could always use a piece of clear Perspex for the front section. It turns out that the lengths of timber purchased as 9”x 1” and 7” x 1” inches measure a few millimetres less (a bit like the shrinking chocolate bars!) so most of the measurements are approximate, but the critical ones that you mention, width & length of baffles etc are accurate. The feeding station is quite large because it was built to accommodate an automatic feeder for when we go on holiday, but in the end it still wasn’t big enough. Thankfully we have a kind neighbour who now steps in to feed them. Good luck! 🙂