Brian Baylis wrote, in part:
"Perhaps the frame is later in '74 as opposed to earlier. I wouldn't be surprised if the '75's all had the oval. I'm still in favor of '74."
I think this frame is later than that, for one reason: the flower cut-out on the dt lug is smaller, less fluffy shape commonly seen around 1977 or 1978. Also, note that the flower stamp on the *fork* IS the fluffier shape. This suggests any number of things. The fork may be a replacement...but I think it's more likely that when this frame was built, forks with both varieties of crown were available, and the frame was simply assembled with the earlier fork-crown.
Although the picture is fuzzy, there's no doubt in my mind that the flower cut-out in the dt lug is the later style. There was a period of a couple of years in the late 70s when Colnagos were made with the older long-point lugs, but the later, smaller, cutout. This transition seems to have ended by 1981 or so, when the medium-point lugs were standard, and the cutout itself may have gotten even smaller. But I haven't checked that latter fact, I'm relying on memory.
Charles "Colnago nut" Andrews