To determine the age of an original LabQuest, look on the back of the unit. There may be a label on the battery door with a serial number on it.

If the unit has a barcode with an eight digit serial number below it, and the first two digits of the serial number are 12, it was made in 2012.
If the unit has a barcode and an eight digit serial number, and the first two digits are not 12, the first two digits are the year it was made, (20XX.) In 2010 and 2011, units shipped within a month or two of being made.
Units with a serial number of 5 or 6 digits were made between 2009 and 2010, or it was made before then but came in for repairs and so was issued a serial number.
If you don’t have a label on the battery door, or there isn’t a serial number, your unit was made between 2007 and 2009.