Well, I need to apologise for getting the (1980) date of my visit to Cinelli wrong but I didn't anticipate that the date would be so important. I visited Cinelli Milan in March 1984, the year of the LA Olmpics.
I've checked the exit dates in my old passport and remembered that my wife's brother was killed in a car crash while we were in Paris in February 1984.

I've done a little research and here's my take on Cinelli and Centurion:

1.Columbus bought Cinelli in 1978 primarily for the aluminium components business which made up 80% of Cinelli sales - handlebars, stems, seat posts etc.
2. Luigi Valsasina hand-built small numbers of Cinelli frames at the Milan factory, using the traditional hearth method - a cottage industry.
2. Luigi Valsasina continued to hand build Cinelli frames in Milan after the Columbus takeover and was still building them when I visited in 1984.
3. Cino Cinelli had no personal involvement in the Centurian project.
4. Under Columbus ownership, Mario Camilotto built Centurions in his factory using Cinelli lugs, dropouts, bottom bracket and his own (normal) seat stay design.
5. Centurions were mass-produced using almost identical components to Cinelli frames built in Milan.

Exerpts from: A VISIT WITH CINO CINELLI by David V. Herlihy

"I approached a modest villa in the picturesque Tuscan countryside, on one unforgettable fall afternoon in 1986...
"Ever since he retired, almost a decade ago, severing all ties with the company which still bears his name, bicycles are no longer an important part of his life....
"Bicycle stems and bars were always the mainstay of Cinelli's production, consistently accounting for at least 80% of his own sales.....
"Frame production, however, could not be readily multiplied without a significant decline in quality. Although some Italian frame makers succumbed to the temptation to industrialize their production, Cino stubbornly resisted.
"His track frames were in high demand by Olympic federations that were free to chose whatever equipment they deemed best....
"Frames were only consigned per custom-order, and customers often had to wait months for delivery, or even longer when he had outstanding orders from Olympic athletes....
"Today he proudly affirms that "no Cinelli was ever assembled outside my factory." He notes that an American businessman once approached him with a plan to produce Cinellis in California on a larger scale, but Cino would have none of that....
"The fabled frame was the result of Cino's yen for a more rigid design. To this end, he conceived sloping fork crowns and the peculiar "fast-back" seat post-bolt system....
"Early on, the hired a Bianchi frame maker, Luigi Valsasina, to assist in frame production. (Now 85, Valsasina left the firm a few years after Cinelli's own exit)....
"Yet for all his innovative spirit, Cino is surprisingly conservative about certain things. He doesn't like the new Cinelli logo (a multi-colored "C"), for example. "I guess they felt they had to change something," he allows, "the way a new boss rearranges furniture"....

I look forward to comments. Moving forward, where and by whom are the current SuperCorsa and SuperPista built?