The 150.511, and some of the 150.501 and 110.501 were not the 'economy' versions.

The cal.15 models seem to have been less expensive than the cal.11 versions, which makes sense. The catalog price list dosn't seem to mention the 'economy' version. I think the case material was different between the 'economy' and standard models.

Does anyone have scans of a price list that shows the relative price of the 'economy' models?

I did a double-take seeing the Monza pic in this '78 catalog, with two white sub-dial hands, until I realized it was the cal.11 version. the cal.15 version all seemed to have one red and one white sub-dial hand.

FWIW, my Monza 150.501 is one of my favorites, on a black 'large hole' strap. I don't wear it all that much for fear of wearing off the black finish, but it keeps excellent time on the winder, and even better on the wrist.