Yes. I have 2.of the 401s and one 601. I thought that it looked clunky and didn't recall ever seeing a stem like that for the 401 churchwarden. Looks like someone did a switcheroo.
My guess is it’s the same stem made for both all the time, just a different bend. They are similar lengths, but not exact so who knows. This 401 looks like it has a 601 for sure.