It's post 1986 based on the decals and a higher end model based on the extent of chrome on the stays. However, there were several models with both SL and SLX tubesets that had the same external features as shown and mentioned. The only way to tell for sure is to remove the bottom bracket and look inside the shell to check the ends of the tubes and chain stays for helical ridges.

The lower stack of the headset appears to be era correct New Dura-Ace, minus the sticker. If so, and it is OEM, it should be either an Equipe or Equipe Pro. Date codes on the headset and bottom bracket may help determine the exact year and consequently the model.