Personally, I don't think the Simplex stuff would have come original on that bike from Masi. Especially not at that time. In the (very) early days you might see Magistroni parts on a track bike, but that's about it from what I've seen. Even with the occassional rift between Faliero and a supplier, it probably never had anything to do with Campagnolo. The rifts seem to be with Regina and Cinelli, and possibly Nisi or Fiamme. Thus the Everest or Sedis chains, and 3TTT bar and stems and saddles, along with Martano rims. I suspect someone bought the frame with a few parts on it somewhere along the line and put the parts they had on hand on the frame. I'm reasonably certain Masi never attempted to make a "lower line" or budget priced bike until the 90's or so.
La Mesa, CA
Given all of the recent discussion about Simplex and Campagnolo, my purchase of the day will have a bit of relevance. I bought a Masi Special today that Brian has estimated to date from about 1968-69. Well surprise, surprise it is equipped not with Campagnolo derailleurs but rather with Simplex. It has what appears to be a Simplex Prestige Criterium rear derailleur. I'm not sure whether this was by choice of the buyer or by Masi. It could perhaps have been a way to offer a cheaper model as the bike also has what appear to be Campagnolo Tipo hubs, lesser 3-arm alloy cranks and a traditional style steel seatpost and clamp instead of the alloy microadjust ones. It could also have been in one the periods when Masi was cut off by the Italian suppliers. This was apparently known to happen with Masi as he seemed to often 'overly extend' his credit with suppliers. Lastly, it could have been simply because somebody thought them to be 'better'. I hope to receive the bike from Italy in time to bring it to le cirque.