They appear to be the same model, but with the stripes/grooves running in different directions. I've seen a gold-colored version of the first one in a lot running now, but no one has said what the pen is called. Chrome over brass, with a plastic connector between the halves that is stamped twice with "Paper Mate USA." The button is faceted around its diameter.
Looks like it's a Capri, based on what you've shown there, Mike. I can't be of any help, as my Papermate knowledge is limited to the Malibu and Profile, which I own, plus the modern pens. You did very well for the price paid, since many examples of old Papermates are in very rough condition, or outrageously priced.
I like Papermates, as they were around as I grew into my awareness of, and appreciation for, nice writing instruments during high school.
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My shirt came to me, wrapped up all in black, something funny told me, I'd have to send it back.
Although I couldn't make it fit, I knew I'd have to try. Now I'm telling all of you, I will never buy....
Apparently the Capri went through several variations; I have one of the second Mark III models as well, and one Lady Capri (with another on the way). Those took one of the short "piggyback" refills, while the Capri took two. Good luck finding working NOS refills of that kind!
I have a Papermate Silhouette BP I bought for $5 several years ago at Walmart. It takes the standard Papermate Lubriglide refill. Made in Japan, it's very well built, but not as nice a pen as your Capri is, IMHO.