You could be right, but some specialists in Cinelli (not me!) are here and are trying to help you. It's not a problem that you aren't a Cinelli expert. If you can get more pictures, we could all tell you more

I think the original steel crank, bottom bracket parts, and pedals are significant clues. If the seller still has them, perhaps he can throw them in.

Another point: the headset on the rebuild is Record, not Super Record. The Record headset was the absolute best/smoothest one available (IMO) until the Super Record came out. The Super Record was absolutely not contemporary with that frame.

The key outward difference is that the Super Record was alloy, not chromed steel.

If the races of your Record are in good condition, it will last most of your lifetime if you overhaul it once a year or after a major rain ride. Same for all your other high end bearings on that bike. Very good quality materials and design, but usually not much attention was paid to gaskets or seals to keep water out. In some cased they had labyrinth seals to reduce water intrusion, but they don't do the whole job.

Overall, my guess is that it is a Cinelli and more likely to be a SC than a Model B or Riviera. Based on the cotter-pin crank, it might be from the 1950s or up to the mid-1960s. Steel cotter-pin cranks were used in serious professional racing into the '60s, because teams were worried that alloy cranks were too new and unproven. It is NOT a sign of a mid-range or low-range bike.

The stem could have been sourced through any of a number of channels for the rebuild. The original one looks to have an oval logo on the front of the handlebar clamp, which could have been an original Cinelli. If the bike was originally supplied with a Campagnolo rear derailleur, it was most likely a Gran Sport or a Record, not a Nuovo Record.