Subject: Correct Guzzi History on Stock Eldo Mufflers?

What is the story on the Mufflers equipped on Eldorados from the factory? Were they all slash back style mufflers as many Guzzi-ists adamantly believe, or did some come with the rounded pea shooter type mufflers as shown in many of the Eldo print ads from the early '70s period.

Can anyone verify the correct type by year?

Thanks,

Mike Shiro