In the absence of a cephalium, I would say that your plant is probably Buiningia (syn. Coleocephalocereus) brevicylindrica.

And James, considering the high level of trust I have in your thoughts concerning these cephalium bearing plants, I will be more than willing to run with your ID.

I thank you.

Al

And James, considering the high level of trust I have in your thoughts concerning these cephalium bearing plants, I will be more than willing to run with your ID.

I thank you.

Al

Now---How did I manage to do a double post?
James, is my message getting through to you?
I am truly grateful.
Al

No problems here, Al.
BTW, Buiningia (syn. Coleocephalocereus) brevicylindrica often maintains a globular shape after reaching maturity and setting a cephalium:

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James