You are of course absolutely right! You're sat there looking at the physical machine with two processors in it sat right in front of you with some plonker on the internet telling you otherwise!
I take it all back and apologise... my mistake completely! I don't know why I had it in my head so firmly that there was only a single processor option for the June 2003 PMG4 models, but I managed to get onto Apple's website from July of 2003 and here we are, in black and white:
View attachment 1969164
Sorry sorry sorry!
Now I am kind of jealous though... I want your dual 1.25! I currently have a single processor 800Mhz Quicksilver. Though if your MDD is anything like mine its a noisy little bugger!
Sorry again!