Old red Mercedes – completely matt – how to proceed?

Hello, I have a W201 in red here. Well, it’s not really red anymore. I also freed the car from moss for the time being. I only have a cheap plate machine available. I fought with the bonnet today. The result was not as good as I would have liked it to be. On the fender I polished with red-white, but laboriously ok. The bonnet barely went with it, I passed with Menzerna, went well, but the result as I said could be better. Red white dried immediately, could hardly be polished any more. Do you have any tips? And with what would you seal the red after the polish?