Have you tried Ian? viewtopic.php?p=43258#p43258
Or I have used a guy in Italy a few times when I can’t find something and don’t feel like hanging around for something to turn up. He sells a few bits on eBay in Italy but I just ping him on WhatsApp and ask if he has what I’m looking for. Downside is the shipping is €24 but if you need anything else, he will combine stuff up to 1kg. He’s been reliable and ships quickly - can share details if you want to try him. I had some images of stock from a few months ago and there were side panels but can’t say if they were the ones you are after. Found an unobtainable Kanguro chain tensioner wheel from him last month! Just had to buy some other bits to justify the postage not being the most expensive item.