If DUCO 73605 is the code,
this thread gives additional code: Charcoal - DUCO 73605 (Dupont DS174)
Silver Metallic - DUCO MM313 (Dupont 94162)
The Ditzler (PPG) code that matches the above code is shown on this page. You can call the PPG Color Library to see if they have an original formula, or an "offset formula" (for a matching color), or a modern formula from on original paint chip. 1-800-647-6050 might still be the Color Library phone number. If LonnieC sees this post, he might have a PPG phone number that recently worked for him.
