Ron - Check the Boston Ramp archives for the ground side of ARINC... if you are lucky there was not too much ramp traffic tying up the scanner. Then you can piece together the JFK ARINC or your LGA ARINC for the airborne and Boston for the ground. Did you check your own LGA 129.4 ARINC for the airborne? I know the ground is distorted, but that's because the LGA ARINC ground station is off by 7.5kHz
We need to get one of my wide-band GRR-23's down to your LGA site for that 129.4 and get it on a dedicated feed...