Many thanks to SWLing Post contributor, Mario Filippi, who shares an eBay link to this Panasonic RD-9820–the matching antenna coupler for the Panasonic RF-2200. Mario notes that RF-2200 owners might take note as the auction price is on a more reasonable trajectory than ones have in past auctions. This 9820 also includes the box.
Thanks for the tip, Mario!
Sold for $149 with only one bidder, he got a good deal. Was very surprised.
The asking prices seen on Ebay in recent months, for these units, are as absurd as some of the asking prices for RF-2200s