Actually, I've seen lots of "Pentium 2 450" systems, that when opened, reveal a chip with no plastic case (read: a celery 300/a that has been overclocked), so there might be some truth to it.
I wonder how many people out there now have OC'ed durons and don't even know it. The 1.1 Tbird I bought hits 1.3 at stock voltage, and you couldn't ever tell it was a 1.1 unless you pop the HSF off of it.