okay, first off - WHERE DID YOU FIND THIS? I want to know immediately. Whether or not to use it, a toss-up. Be great for the wow factor, but if you do you destroy the pristine quality of this find as an artifact.
It came from an estate sale with some other unbelieveable old items. At this point, I think I'll keep it unused primarily due to its relative scarcity. I think I saw that someone else on this forum has one.
I'd use it at least once to try it.
If it was Marylin Monroe's soap and there was a blond hair stuck to the puck I might feel differently....
Otherwise - I'd lather it up right away. I love old soaps. To me they aren't artifacts for a museum - they're little shards of history that offer a glimpse into the luxurious simplicity of days gone by.
I would use it. I just acquired two pucks of vintage Williams off Ebay and you can bet that I'm going to use them in my rotation. The lather the vintage tallow soaps make is just amazing. Its slick, thick, and gives plenty of cushion. You owe it to yourself to at least try it a couple times.