Asterisk/Elastix/FreePBX - replace caller ID using custom context

I followed the instructions here: article in order to remove the incoming Caller ID.  The manager wants the calls to be unknown so that annoying customers are not avoided by the staff.   They have 2 lines which are answered differently so they want to know which line was called in on.  They are using an FXO card.

I edited /etc/asterisk/extensions_custom.conf to include:

[from-zaptel-callline1]
exten => _X!.1.Set(CALLERID(num)=Line1)
exten => _X!,n,Goto(from-zaptel,${EXTEN},1)

[from-zaptel-callline2]
exten => _X!.1.Set(CALLERID(num)=Line2)
exten => _X!,n,Goto(from-zaptel,${EXTEN},1)

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I then set the context in /etc/asterisk/dahdi-channels.conf to:

;;; line="2 OPVXA1200/12/1 FXSKS"
signalling=fxs_ks
callerid=asreceived
group=0
context=from-zaptel-callline1
channel => 2
callerid=
group=
context=default

;;; line="3 OPVXA1200/12/2 FXSKS"
signalling=fxs_ks
callerid=asreceived
group=0
context=from-zaptel-callline2
channel => 3
callerid=
group=
context=default

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After amportal restart incoming calls are terminated with the following:

   -- Starting simple switch on 'DAHDI/4-1'
  == Starting DAHDI/4-1 at from-zaptel-callline1,s,1 failed so falling back to exten 's'
  == Starting DAHDI/4-1 at from-zaptel-callline1,s,1 still failed so falling back to context 'default'
    -- Executing [s@default:1] Playback("DAHDI/4-1", "vm-goodbye") in new stack

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Any help fixing the context so it does not fail but rather replaces the caller ID as it should would be appreciated.

Thanks.