Sent an email (on Nov 10, approx 9am) as described by aerobinso. Proactively attached an image of my World Elite MC. Just received the following email back:

"I received your recent inquiry concerning your Hertz Club Gold membership status.

I am delighted to inform you I have upgraded your membership to President’s Circle Gold. Please allow 24 hours for this information to update in your online profile. It is not necessary to have the card to begin enjoying the benefits of your upgraded status. The Hertz website allows members to print new cards online. Once you are logged onto our website, click on “My Account” and then “Print Membership Card” under the navigation.

As a President’s Circle Gold member, you will appreciate benefits such as guaranteed vehicle availability and guaranteed one-car-class upgrades with a two hour notice at participating Hertz locations in the US and Canada, no blackout dates for certain vehicle classes on special offers, preferred parking spaces for your convenience and 675 Hertz Award points (the equivalent of one non-peak rental day) automatically deposited into your Hertz Gold Rewards account after the completion of every 15th rental. Additionally, members who participate in the free Hertz Gold Plus Rewards program receive 25% bonus points on rentals. If internationally registered, the benefits would apply for participating locations in Europe.

Your loyalty is important to us and we trust your future card rental experiences reflect that."

Thank you very much! All very easy.