Unfortunately that part number has a "Country of Origin" of USA. Which is a fancy way of saying it was made in a random sweatshop and they put it in the retail box in the US.
They want you to think it is made here, but it isn't. There is a reasonably good chance that the new regulator is just bad out of the box. Many (most?) are these days.
An original from ebay like Hotrod Lincoln recommended is going to be your best bet. The procedure for adjusting them is available and they last better than the modern junk.
