It's a 1973 P13-9. You have a beautiful, original bike that was a bargain at $400.
The P13 doesn't have eyelets (the P10 does), and the P13 uses the three Campy clips on the top tube for the rear brake cable (the P10 has braze-ons on the top tube for the rear brake cable). Your bike is "Silver Mist"...
The catalog photos show the 1972 seat tube "Olympic Rings" decals because the photos are taken in the fall of the previous year. The 1973 Paramounts only had the World Championship rings decals as on your bike.
If the rims are Mavic Championnat du Monde - Montlery tubulars, they are original. That's what came on my December, 1972 Paramount.
From the 1973 Paramount Catalog:
1973 Consumer Catalog: