Alphas came out in 1960 and were among the first Accutrons. The literature says they were made through 1965 but I have never seen one that new. The latest one I can remember was dated 1962. All of them were solid gold.
Here's one of mine from 1961.
Bulova introduced the Accutron at BASELWORLD on October 25, 1960. The 14k gold "Alpha" Model 541 was most certainly one of the first Accutrons presented. The "Alpha" style case was already in production at the time and had been used to house a 23 jewel movement in "President" model watch. Two other styles in solid gold may have debuted at the show or followed soon after. They were the "TV Case" Model 521 and one that had the asymmetrical or football case. The solid gold Accutrons sold for $250.00 up and no doubt met with some price resistance. To overcome the price issue, Bulova introduced the Model "203" ($192.50) in a stainless steel asymmetrical case that was marked "Bulova Stainless Steel Patented Waterproof 14K Inlay" with the date code "M0". In addition, two other gold cased Accutrons were produced in 1960. One was a round case with a coin edged bezel and the other was a variation of the asymmetrical style. Other combinations of dial and band doubled the number of Accutron models that could have had the N0 date code.
There may be documentation that the very elegant scalloped lug (long lug) case was made in 1960 (N0) but if so, I just can't find it. However, there are surviving Bulova ads that support the notion that it was the first case used for a factory made Spaceview in 1961. The Spaceview "Alpha" would have come in second with the first being advertised in 1962.