I've tried to merge attached sig files:

cdc11.sig
fp11.sig

the merged file does not contain following classes:

+ Class java.text.DateFormat$Field
+ Class java.text.MessageFormat$Field
+ Class java.text.NumberFormat$Field

Details:

cdc11.sig generation command:

Execute:Java13CommandLauncher: Executing '/net/jse-st01.russia/export4/java/re/jdk/6/archive/fcs/binaries/solaris-i586/jre/bin/java' with arguments:
'-classpath'
'/set/java/re/sigtest/2.2/archive/commercial/binaries/sigtest-2.2/lib/sigtestdev.jar'
'com.sun.tdk.signaturetest.Setup'
'-static'
'-CheckValue'
'-NonClosedFile'
'-apiVersion'
'1.1'
'-Classpath'
'/set/java/re/cdc-spec/1.1/archive/fr/binaries/lib/btclasses.zip:/set/java/re/cdc-spec/1.1/archive/fr/binaries/lib/cdc.jar'
'-Package'
'java'
'-Package'
'javax.microedition.io'
'-FileName'
'/net/zenit/export/users/ds58869/MMAPI/ws/mmapi-tck-1.2a-build/MMAPI-TCK_12/tests/api/signaturetest/cdc11.sig'

fp11.sig generation command:

[run-sigtest] Executing '/net/jse-st01.russia/export4/java/re/jdk/6/archive/fcs/binaries/solaris-i586/jre/bin/java' with arguments:
[run-sigtest] '-classpath'
[run-sigtest] '/set/java/re/sigtest/2.2/archive/commercial/binaries/sigtest-2.2/lib/sigtestdev.jar'
[run-sigtest] 'com.sun.tdk.signaturetest.Setup'
[run-sigtest] '-static'
[run-sigtest] '-CheckValue'
[run-sigtest] '-NonClosedFile'
[run-sigtest] '-apiVersion'
[run-sigtest] '1.1.2'
[run-sigtest] '-Classpath'
[run-sigtest] '/set/java/re/fp-spec/1.1/archive/fr/binaries/lib/btclasses.zip:/set/java/re/fp-spec/1.1/archive/fr/binaries/lib/foundation.jar'
[run-sigtest] '-Package'
[run-sigtest] 'java'
[run-sigtest] '-Package'
[run-sigtest] 'javax'
[run-sigtest] '-FileName'
[run-sigtest] '/net/zenit/export/users/ds58869/MMAPI/ws/mmapi-tck-1.2a-build/MMAPI-TCK_12/tests/api/signaturetest/fp11.sig'

SigTest execution command:

java -classpath javatest.jar;sigtest.jar com.sun.tdk.signaturetest.Test -static -FormatHuman -Files C:\MMAPI\MMAPI-TCK_12\MMAPI-TCK_12\tests\api\signaturetest\cdc11.sig;C:\MMAPI\MMAPI-TCK_12\MMAPI-TCK_12\tests\api\signaturetest\fp11.sig -Classpath C:\MMAPI\mmapi_cdc-1_2_01-rr-bin-b01-windows-i686-26_oct_2006\Optimized_nosym\lib\rt.jar -Package java -Package javax -ErrorAll -Write C:\MMAPI\WD\WD08\merged.sig