Okay, I'm dense. I searched under "how to upload a photo" and "how to post a message" and "how to add a photo to a message thread," did not think to look at "how to post to the gallery" for instructions on how to add a photo to a message. The mind works in mysterious ways. Anyway, I get it now. THX
Luckily my Cayman stays in a warm 1-car garage. But the follow-on blizzard today (Tuesday) obliterated what was left of my street in the morning. Furious afternoon shoveling of the driveway and a late visit from a plow down the street at least left some packed-powder pavement that will allow me to take the Volvo tomorrow.