I have a dressmaker's ham in L.A. but I forgot to bring it with me when I moved my sewing machines to Palm Springs.

If you are making masks and want to press the curved seams open, you can use the narrow rounded edge of the ironing board. It works almost as well as a ham. If you have a sleeve board, use the rounded edge of that. You have to slip the mask onto the curved end so that part of it is above and board and part of it is beneath.

Yes, I am. I have been using the edge of the ironing board for this; but now that I know these exist, I could see having one. Or the sleeve board: that would be handy too.

I have been known to roll up a towel to get the shape I needed. Certainly not perfect, but I made it work.

If you Google "Tailor's ham", there are several YouTube videos of how to construct one.