Tom Landry has rung down the curtain in Dallas on Thomas (Hollywood) Henderson and sent the mercurial former Cowboy linebacker to Coach Dick Nolan's New Orleans door with at least a phone-ringing endorsement.

Let Henderson tell the tale of his meeting this week to ask forgiveness of the coach who fired him last November as a disruptive influence on America's Team:

"I tried everything, I even offered to cut the lawn at the practice field on Saturday. The bottom line was I couldn't even come back and clean cleats. I did everything but get on my knees and he still said no.

"I threw my ego out the window . . . But to no avail."

How about the Saints? Henderson asked. Landry rang up Nolan. And? Let you know later, says Nolan. . .

Baseball meetings in New York yesterday: Al gave the Oakland Coliseum board until Tuesday to accept the $4 million buyout for removal of the A's to Denver. NL unaminously approved sale of the Mets, and while the new owners said Joe Torre stays as manager for 1980, they told Joe McDonald, general manager, to go ahead and look for another job; it appears he will find front-office employment with the Texas Rangers . . .

Hank Peters, a hard bargainer on Oriole player contracts, has agreed with new owner. E. B. Williams on a four-year extension of Peters' general managing pact when it runs out after the 1980 season . . .

Plaintiff David Manning Jr., 22, of Buffalo got the word in federal court, Boston yesterday: Ross Grimsley, then an Oriole, did not intentionally throw the ball that smacked Manning, then 17 and of Pembroke, Mass., in the face in the Fenway Park stands in 1975. Manning claimed the left-hander, now of the Montreal Expose, flung the ball from the Oriole Bullpenin anger at heckling from the stands. It slipped, Grimsley maintained. Judge and jury cleared Grimsley of malicious intent and of negligence; also took O's and Red Sox off the hook . . .

Dave Winfield was in town yesterday to accept the 1979 Brian Piccolo UMCA humanitarian award at the National Capital Y. The big Padre outfielder, so generous in civic and youth work in San Diego and St. Paul, Minn., is to be received by Jimmy Carter at the White House today . . .

Close your eyes, Superstars (taped) CBS-TV watchers: The winner (eventually) will be . . . Charles White, USC's Heisman man, $35,425 worth, after the various-sports-but-not-your-own competition in the Bahamas. Second, Russ Francis; third, Phil Garner; fourth (ta-da!) Joe Thiesmann . . .