I just did my '68 a couple of weeks ago. I didn't find an argent that I was looking for but I had a can of VHT SP127 Universal Aluminum. Looked perfect to me.
Similar deal with painting everything black first and then masking off for the silver. The back half of every individual vane is black on the '68 also.
I had to touch up a few spots after this photo. For that, I sprayed the paint on a piece of glass and used a small brush and MORE masking tape. A LOT of masking on this deal... I mention that because if you can't find the marker, you might be able to do the same for the argent on the front edge. Small artist's brush with bristles cut almost all the way back to the handle or even one of those small sponge paint applicators you get at the hardware store in the paint dept.
