342-0134 etc. seem to be actual model number of the IC's. They are 2764 EPROMs. However, I don'get how they could actually become corrupt, as they don't have the "window" on them. Maybe the problem lies elsewhere. Anyway, checking the content won't hurt.
Here: (Very good site, with rom images for every chip)
http://www.applelogic.org/APPLEASICs.html
Also take a look around these two links (if you don't know them already):
Misc Rom images:
http://www.apple2.org.za/gswv/a2zin.../Archives/A2MiscROMimages/A2MiscROMimages.htm
Catalog of Roms, if you go up in the misc directory, there's a world of information:
ftp://ftp.apple.asimov.net/pub/apple_II/documentation/hardware/misc/Apple II Common ROM Numbers.txt
