GPz1100 - Well, I finally took the plunge, and it's now working. My original land line number (area code 212) has been ported successfully to the GV account, and calls to and from that number are working in the Obihai 202 on the cheap plastic phone on Line 1.
Whew.
I was worried that the earlier glitch meant I'd have a problem, but at the end got lucky.
FYI - I did NOT re-try with a new GV account because I finally understood (from Steve's posts elsewhere) that I'd need a different "linked to" outside number, and I don't have enough outside numbers to experiment like that.
Have not yet set up anything special on the GV voicemail or anything else.
And in 10 days I am going to do the whole thing again for my second land line - my wife's important number.
Thanks!!