By 1962, Benelli had combined forces with MotoBi and were utilizing the famous “power egg” engine in 125cc and 200cc variants (which would eventually become 175cc and 250cc options).
The 125cc (123.7 if you’re particular) option put out a claimed 16 horsepower and 10 ft-lbs of torque, good enough for a top speed (again, claimed) of 75 miles per hour. In a 1968 ad, Benelli actually said “We say 78 mph but people tell us 90 mph!” If you’re curious, here’s a shop manual for the Sprite 125/200 as well as the Barracuda 250 from Cosmopolitan Motors, the Benelli importer at the time (who offered an impressive 25 month/25,000 mile warranty).
This example has been “modified for various vintage events this bike has participated in,” based on what I’m seeing I’m guessing the seller is referring to some Moto Giro events. It appears to be missing the original speedo/odo but otherwise the modifications don’t seem to detract too much from the originality.
Find this Sprite for sale in Sacramento, California for $3,750 here on Facebook Marketplace (you will need to be a member of the AHRMA SWAP MEET group to see it).