Radio Newsbriefs:  WABC (770 AM) will mark Bob Grant`s 60 years in broadcasting this Wednesday, May 14th. Grant, whose radio career began in Illinois and California, has been heard on New York radio since 1970, with stints on WMCA (570 AM), WOR (710 AM) (twice), and WABC (also twice).    John Gambling returns to his long-time radio home, WOR (710 AM), as of Monday, May 5th, after more than seven years on WABC (770 AM). Carrying on a family tradition going back to 1925, Gambling was heard on WOR from 1985 until September, 2000. His new show will feature Joe Bartlett, Donna Hanover, and weekly appearances by Mayor Bloomberg, who was also featured on Gambling`s WABC program.    Rich McLaughlin, long-time Alternative programmer at Sirius Satellite Radio, has been named as Content Director for the new WFUV (90.7 FM) HD channel and web stream aimed at younger listeners. McLaughlin is a Fordham graduate and worked at WFUV during his college years.    The new WNYC Radio/PRI morning show, "The Takeaway with John Hockenberry and Adaora Udoji", debuts on Monday, April 28th in New York City, Boston, and Baltimore. The news/talk show will air on WNYC-FM (93.9) from 6-7 AM and on WNYC-AM (820) from 8-9 AM; Morning Edition will continue to air during the balance of morning drive.