Uncle Melvyn made a bespoke cover for our antique leather suitcase from the same vinyl material as our hood. Looks really smart and totally waterproof.
Downside is that the suitcase is far to heavy to use and we're considering our options for the upcoming touring season.
We also have one of the Morgan leather suitcases and in the end we decided it was impossibly heavy. I looked around and eventually found a suitcase that is reasonably light, looks the part, and has a zip that is almost completely covered. In fact in a light and brief showe I would not even bother to cover it. A clear vinyl cover is available and I use that if it looks like rain.
The case is the Brics Bellagio. They are not cheap but they are very, very good.
https://www.brics.it/en-gb/catalog/detai...D%3D&icf=20