Those look like the stock strings Head put in them at the end of production. Is it a Designed in Austria/chinese version?. If so, those string are probably from around 2001. They were selling them pre-strung with Head Syn Gut 16 for around $59.99. Not bad.
Great rackets, all the versions are great, Austrian, chinese, Czech. No bad PT 280's IMHO. I have them all and use them interchangeably. Really like them.
How much did you steal this one for?
Different companies measure racket heads differently. The PT is about 95-ish, 97-ish whatever. It is a mid plus. Beam width is 20 mm. Flex is around 58 give or take a couple of points. Flexy enough but not a wet noodle. Stock weight was right around 12 ounces, think the stock balance was 6 points.