I too have been searching for clips and a lock. Tech support determined that my box (lower) was from 1972 and was made by Matco when the were together with MacTools. The clips he believes I need are part#XCS-A. $24.00 for a 10 pack and no luck with the lock. Looks like a push type from an old file cabinet might work. Here's some pics (ignore the metal tab coming out from the lock hole, it keeps the lock rod from jamming up the draw with no lock in place)