Hey Phil,
The original factory metallics were in fact a 3 stage base/color/clear - so that's not an issue to go that way today, but with more modern & durable paints which are available.
Today's urethanes are probably going to be the most durable you'll find, as the others above have said, & from what my Dad had told me about them (he invented them & urethane varnish back in the 1950-60's while at Koppers). While urethane paints were available when our 914s were mfgd., I'm not sure that they used urethane paints on them back then.
I'd recco you stick with only top line paints, with a good epoxy primer/sealer to treat the rust from bare metal under it (also top quality). The PPG named above, Dupont, Glasurit & Sikkends are all recognized as top best-of-the-best for paints/primers/sealers, & a good local paint shop will know that.
If you're not skilled in body work, then you should probably have them work up from the bare metal to do all the block sanding & other skilled work to get a baby's-bum finish under the paint (I'm not).
Here's a source for the paint colors & mfgrs., but I think that some of the other mfgrs will have it too (BTW - Sherwin-Williams is NOT a top quality). IIRC Glasurit/Dupont has a Classic paints line with the 914 colors too.
http://paintref.com/cgi-bin/colorcodedispl...975&rows=50IIRC - they used PPG on my 73 2L back in Summer 76 when I had it repainted to Copper in 3-stage.
IIRC Jeff Bowlsby's website has the factory metallic 3-stage repaint guide for dealers in his Tech Docs. section or somewhere on there.
http://bowlsby.net/914/Classic/As for the sail trip - I too prefer the black vinyl sails & black satin/semi-flat rockers look cuz it make our 914s look even lower slung, & if it came that way from the factory (either as a separate option or as part of the Appearance Group) & you're wanting to keep it at max. value it should go back to original with sails.
But if that's not your preference, then do at least save your hardware & trim if you or a FO wants to put it back to original. The mounting holes will also need to be filled to delete the trim/vinyl option, but you may want to try to do it in a reversible way, & do take some measured pix (tape measure/ruler from mounting holes to reference points), so that you or a FO can find them later.
Good Luck!
Tom
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