Cast Metal Nude Lady Letter Opener/Knife

This letter opener belonged to my Dad and he had it as long as I can remember and I'm 73 years old. I'm pretty sure it was made in the 1940s. It is cast metal, either cast iron or pewter. I suspect the latter as it has a light silvery gray color. There are some faint marks on the back of the blade that may have been printing stamped there that has worn off. I used this to open all of my mail. As I had no intent to sell it, I did sharpen the edges of the blade to easily slice open envelopes. It would serve equally well as a stiletto and may have been made for that purpose.