re : The alt-v combination does not bring up any kind of menu.

That's because you should just press 'Alt' key and not 'Alt+V'.

Pressing 'Alt' key will get the 'Menu Bar' toolbar to appear temporarilly. Then select 'View' > 'Toolbars' > 'Menu Bar' to set as permanent. Select 'View' > 'Toolbars' > 'Composition Toolbar' to get the toolbar that contains the 'Send' button etc.

Thanks for posting a possible solution.

Hitting the alt key alone doesn't do anything either. On the main Inbox tab I have the usual Get Messages, Write, etc. To the far right, there is a drop-down menu with things for the Inbox tab such as View, Find, Print, etc. The View option offers such things as Folders, Message body Today's pane, etc. No joy there. The Tool option offers Address Book, Import, Chat status, etc. No joy there either.

Nowhere do I find a Composition.

Just to make sure we're on the same page, this is on an up-to-date OSX machine. The Thunderbird release is 68.8.0 and it advises me that the app is up-to-date.

What am I missing here?

re :When I click the "Write" button to create a new email, the window that comes up does not have the commands ribbon across the top. Most importantly there is no send button,

You are talking about there being no 'Send' button, so obviously you are in a 'Write' window. Therefore all my comments were based on you opening a Write window.

Open a Write window as if you want to compose a message and then Press and release the “Alt” key on your keyboard. This will temporarily show the menu bar. Then make 'Menu bar' toolbar permanent and then select to show the 'Composition toolbar. All info previously supplied.

re :Nowhere do I find a Composition.

That's because you are looking in the main UI and not where you create, compose emails. So, you would find 'Composition Toolbar' in the Write window where you compose emails. But you need to enable the 'Menu Bar' toolbar first if you cannot see it.

re :Hitting the alt key alone doesn't do anything either. On the main Inbox tab I have the usual Get Messages, Write, etc. T

You seem to be talking about the main UI, which is obviously not were you create, compose and send emails. You must open and be focused on the 'Write' window.

Actually both -- UI and Write window. In the Write window beginning at the very top...I have the red/ yellow/green then in the middle, Write: (no subject) The very next row down is the From row, under that is the To row. Then the space for your text. No response to the alt key. Here's a screenshot of the Write window.

You are using a mac... very important to state that as everything changes in that situation and you have an apple menu permanently displayed.

Try right clicking (command click) the window titlebar. In Linux and Windows that offers a pop up menu. Hopefully it does in MACOS as well.

A thousand apologies! I just assumed that Thunderbird ran exclusively on macOS. I can certainly see why we weren't getting anywhere.

Update: As I was writing this, I was also still checking through the Preferences options, finding nothing. Then I tried the commands across the very top of the main window -- File, Edit, etc. In that lineup, I find View. I hit the View => Tool Bars option and find a Mail Tool Bar option. I guess I had assumed that that only applied to the main window. When I selected it, I found my Write window commands had come back.

In any event, thanks a bunch for working with me on this problem. Your patience is appreciated.