Did you mean 26.8mm? That’s a much more likely size for an older Schwinn, and quite a few other bikes of that era, such as most Miyatas and lots more.

The seatpost you’re seeing on that Paramount is a classic two-bolt Campagnolo. Expensive, somewhat rare, highly sought by many around here, and hard to use without the special Campagnolo wrench.

I found this really long setback Truvativ-brand 26.8mm seatpost for my Miyata 912 at the local used bike parts emporium. Note: the Truvativ shaft was black, but I just finished polishing the visible portion.



And there’s this UNO model in 26.8mm that’s not quite as long in setback, and has notches for the saddle angle adjustment, so doesn’t allow quite as fine adjustments. Here’s a photo of it, which I’m no longer using. If it interests you send me a PM and we’ll work something out.