FWIW, you can easily get a Grado P Mount into a half inch adapter with a plain old file. You just need to file off about 0.5mm from the underside of the adapter. You could file the top of the cart down, but why screw up that pretty metallic painted lettering? It seems to me that Grado took some pains to make their P Mount carts not to easily fit standard adapters at some point. I've got some older ones that slide right in--back when Grado marketing thought it was prudent to sell a "universal" cartridge. They also had P Mount carts with the 1/2" ears also--looks very strange, but no mount adapter needed. How Grado thought that was a good look, I'll never know. Can't imagine they sold many of them. However, you still needed to do something for the wires--little sleeves was the answer. Yick on looks and clumsy for adapting. Even now, they don't use a different piece for P Mount bodies, they just cut those ears off.
Later on, marketing decided to make the P Mounts more difficult to adapt (for anyone who doesn't own a nice flat file, anyway) by making them a smidge taller.
