What you have there is an Austrian made WEBRA engine, the 6.5 Cubic Centimeters translates roughly into a 40 sized engine.
IF that engine has been well taken care of it is a precision piece of gear that will easily give 10 + years of service.
It is not a screamer but it will deliver some 13.5K RPM all day long and power most Sport AC quite nicely.
You didn't show a muffler with it - or any other photos -I'm hoping that there is no hidden damage etc - the joys of used equipment.
Hope for the best - that should be a GREAT little engine for you!