Ron,
Eric Gardner posted a reply on the 'Silver Metallic Exterior with ??? interior' that answers your question. He shows a table with colour schemes exterior / interior and colour codes for exterior. I don't know if the table is correct regarding the red but I'm sure it's correct regarding the silver, since this is the colour of my replica and I had done previous research and the codes match. The table indicates the red available between 57-59 was Ruby Red with the following colour codes: Porsche #5702, Reutter #702. If you go to the Glasurit site and enter POR #5702, you will find the colour mix you need to do with Glasurit paint to get the right Ruby Red.
I did this with the silver and the colour looks superb.
Hope this helps.
Best regards.
Miguel Caldeira Proenca
m.caldeira.proenca@mail.telepac.pt