PHILADELPHIA — Dave Scott is quick to note he wasn’t at Comcast Spectacor when the company sold the Philadelphia 76ers six years ago. The NBA franchise Comcast Spectacor sold for about $280 million in October 2011 was valued this year by Forbes at $800 million and could probably sell for more — the Houston Rockets recently sold for $2.2 billion. Scott, the chief executive officer at Comcast Spectacor, joined the company in 2013 following a 20-year tenure at Comcast Cable. “I know (76ers owner) Josh Harris is a happy camper with what’s going on,” Scott said, with a laugh.