I don't have an example, but it is one that was sold on letraset rub-down transfers around 1980. I tried googling Letraset fonts without finding it, but it might have been a typeface that letreaset licensed from somebody else.
It was made of quite coarse halftones with visible dots arranged as a coarse graduated tint, giving the appearance of bent metal.
This (called Tonal) is not the font but may give you a clue ...
Unlike the example above, only the characters were halftoned, not the background, so the letters themselves were pefectly recognisable.
Oops -- found it already -- it's Calypso ...
Hi ya Harry.
There is a version of this font that was really, really redrawn well. And it's free. Download link is just below the title at the link.
Mike