I don't know what that had but the most popular and adjustable seatpost in that size is the SR MTE-100. The was a guy back east on FB that bought a warehouse last year and had a hundred or so NOS so I picked up a couple to have. Put one on my Tourer for versatility and weight is not a concern. He wanted to sell me in bulk but I am not a reseller so I passed. I may have his info if you would like I can look for. Quite reasonably priced even even for one

Like this SR Sakae Ringyo MTE-100 LAYBACK ADJUSTABLE SEATPOST 26.8mm ONLY! at Yellow Jersey