Slightly OT/High Voltage DC voltmeter help

Help,I need to find someone who could recalibrate a high voltage DC voltmeter for me.It works ok but doesn't display the correct voltage.
http://i200.photobucket.com/albums/aa64/gasnutty/000_0205.jpg
I heard it was from a Tug Boat in NYC Harbor,its old and big and heavy.I thought with all the know how and know who, some one on this board might be able to help.Yes I use this in an Electric Vehicle,Yes it is a bit off topic for this board.I have searched and searched online to no avail.Thank you.

 

Has someone tagged a shunt resistor across the input terminals?

 

I will check but I dont think so...Thank you

 

Thank you ,It was a pair of resistors soldiered into the positive side of the input.They were behind the faceplate and I never had checked there before.Problem Solved.