Correct screws for ARP Odyssey side panels?

Hello all,
I’m the happy / proud owner of an ARP Odyssey 2810 model.
The side panels are missing most of the screws and the ones still there are silver flathead screws which I’m sure are not original. If any of you have any recommendations for the most suitable screws and diameter & length as fitted stock, I would be very grateful. Black roundhead screws would probably look best but I’m interested in what they would have had fitted at the factory.
Many thanks,