would have known exactly what to do and which frequency to call.
Uplinker et al,
"call ground .X" is listed in the FAA documentation/AIP/AIM as meaning "call ground 121.X", if the ground frequency is not in the 121. range, the full frequency will be given.
There are a number of minor differences with US v. ICAO, all notified to ICAO, but nothing like the number of differences notified by Australia.
"next available" is usually pretty obvious, as to whether it is left or right, in all my years flying in and out of the US, I do not recall any doubts.
As far as I am concerned, European countries that conduct ATC conversation part in English and part in the local language are a far greater threat to safe operations, than the ATC English in the US.