Bill,
If you check the ZNY North Mountain feed, you will hear both ground and aircraft on 124.625. Perhaps this is a simu-cast feed tied-in with one of the other North Mountain frequencies, or the feed provided hasn't listed it.
I'm not associated with these feeds but as far as I can tell 124.62 is on the North Mountain radio but not listed, it replaced 134.80 which is listed but has since been moved to the "KIPT Gnd/Twr/ZNY" radio.
On the "ZNY (North Mtn RCAG)" feed you are hearing the controller on 132.15 (sector 74 - Broadway). Sector 74 is frequently combined into Sector 92 Pottstown - 124.62. When combined they put all the aircraft on 124.62 as the primary but the controller continues to simulcast on 132.15. I believe this is what you are hearing.
The fastest way to tell if the 74/92 sectors are split or combined is to note the EWR/LGA arrivals on the handoff from 128.57, if the sectors are split they handoff to 132.15, and if combined to 124.62.
During off peak times sectors 74/92, or just 92, will also combine with sectors 91/93 (covered on the "KIPT Gnd/Twr/ZNY" feed).
On the midnight shift I believe ZNY turns on 127.725 and that this frequency is also on the North Mountain radio but not listed either ?
Dave, any chance the frequency listings for these feeds could be updated to confirm the above ?