OK, here's what I got out in the garage for the silver I used. It's PPG 8967, Astral Silver/Astro Silver (M.B., '80'86/'90). Didn't find anything else on it or where I came up with that shade but I have a can each mixed in Omni MTK & MBC. I looked over my chip books which I thought that was where I found it & found PPG 8568 which is Argent Silver list for both rally wheels & trim on the '78 Chevy page. The 8967 would need a low gloss clear, can't remember if single stage 8568 is a low gloss or will need a low gloss clear.