HP/Agilent Power Supply Age
If the numbers are anything like on HP calculators the unit might have been built ca 1984 according to the site mentioned below.


  Decoding Serial Numbers
  
  Numbers are in the format YYWWC##### where
  
  YY    Is the number of years since 1960. 
  
  WW    Is the week (roughly) in which the unit was made. YYWW is not always exact and sometimes may have gone weeks or months without changing. 
  
  C    Is the country code: A = America (USA), B = Brazil, G = Germany, J = Japan, S = Singapore, M = Malaysia or Indonesia. 
  
  # The serial number within the specified week and year. (This is not included in the Earliest Serial Numbers section because all are assumed to start at 0 or 1.) 
  
  Example: The museum's HP-94F is serial number 2622J00025 indicating that it is the 25th unit made in Japan in the 22nd week of 1986. 


Source: http://www.hpmuseum.org/collect.htm