Does anyone here know Robert Walpole who wrote marvellously informative posts about Pete Seeger and other folk artists on a Facebook page https://www.facebook.com/groups/38510854398

Robert Walpole is, or was, a maths tutor who lives/lived in Jenkintown Pennsylvania. He last posted on the "Pete Seeger" Facebook page on 29 June. A "Barb Borden" has posted that she searched for information and found an obituary. We don't know whether or not this is true.
I found his LinkedIn page but he hasn't posted recently and I can't send a LinkedIn message as I haven't got a premium account.