NJRoadfan, thank you very much for the Logitech Harmony remote info! Unfortunately, I don't have have the original remote of the other devices to capture the button codes from.
By the way, the other devices are Pannys SVHS AG-1980 and AG-5710. Both of which I don't really need a remote control for those two decks to operate their functionality properly. That's my understanding. But the HR-S7900U deck, definitely needs a remote for functionality of that unit. If I'm incorrect in my assessments, please let me know. Yes, I went on a SVHS deck mini-buying spree.