Saavedra derailleurs are Rino's Crono design repurposed for the Argentine market. It seems that the parts were forged by Rino in Italy, but the logos were applied and the derailleurs were assembled by Saavedra in Argentina. However, like the Rino product the rear parallelogram plate is stamped 'Made in Italy'. You can see a brief discussion of this in the interview here.

The Saavedra uses a an excellent slant-parallelogram layout ('borrowed' by Rino from SunTour) and is formed and finished to a respectable standard. Notably, it is fully demountable. There is a decent case to be made that these (and their Rino and Excel siblings) are among the best non-Japanese derailleurs available at the time.

I think that this is a later Saavedra derailleur, dating from, or after, 1982. It has conical allen bolts at the b-pivot and p-pivot and an open loop in the inner pulley cage plate at the tension pulley. Some of its key features may be:

• The logo is red lettering on a silver background, with a raised border only at the top and bottom.
• The main allen bolts at the b-pivot and p-pivot are conical and are not engraved.
• The parallelogram pivots and cable clamp bolt and washer are silver.
• The inner pulley cage plate has an open loop at the tension pulley
• The adjustment screws have very rounded-off heads.

Finally, it is worth noting that this derailleur is startlingly light - at 171g.

• Derailleur brands: Saavedra, parts manufactured by Rino
• Themes: Ultra-lightweight - short cage models
• Country: Argentina, parts (?) manufactured in Italy
• Date of introduction: 1982?
• Date of this example: unknown
• Model no.: unknown
• Weight: 171g
• Maximum cog: 24 teeth?
• Total capacity: 24 teeth?
• Pulley centre to centre: 48mm
• Index compatibility: friction
• Chain width: 3/32”
• Logic: top normal
• B pivot: unsprung
• P pivot: sprung
• Materials: largely aluminium