here's the tutorial I used with my '67 New Yorker:
The Secret to Removing Oxidation and Restoring a Show Car Finish to Antique Single Stage Paints
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A bit involved, but working in stages, I had good results (see attached), and brought it from somewhat dull to nicely presentable. The clay bar made me a little nervous, so I skipped it, but since then, others on here advised me I didn't need to be, so it may be just fine. Main thing is to approach old paint like old leather, it needs moisturizing, which Meguiar's #7 did well. Messy to remove if you apply like the tutorial says, but it really does make a difference. The finish was much easier to work on, and takes wax better after using it. is.
There are plenty of other waxes, etc., to use, avoiding solvents/cleansers seems to be the key. I followed the Meguiar's with Zymol liquid cleaner/wax (all natural) and finished with a coat or two of carnuba. Hope this helps.