While Vintage Shaving Soaps can be some of the best ever made, I don't think I would ever use a vintage shaving cream.
Shaving soap doesn't really change over time besides losing it's scent. Shaving Cream on the other hand goes rancid, and breaks down. There also may be questionable ingredients in it, that won't be allowed in a product today.
Most concerning though, is that the tube itself might contain lead: Sorry, but I am not putting a product that has been in contact with lead for 50 years anywhere near my face!!
~~JOHN~~*Founding member of ALPHA Team*