[Boatanchors] Question for Weston 269 Meter

[William Morton]

Hello All,
Season's Greetings from Minnesota, where it is currently snowing. 

Today's question is about the beautiful Weston 269 meter.  Does anyone have any experience in changing/replacing the background scale?  I have a pair of meters, each with a DC volt scale ranging from 0 to 500.  Unfortunately each of them has been blown (I will spare you the sad details).
I see several for sale on eBay but they are scaled for mA or dB so I would need to change them somehow.  Luckily I can take my blown meters apart for trial purposes but I would be grateful for some advice as to the proper method.
Alternatively, if someone has a pair already scaled to 500 VDC and is willing to part with them I would be very interested in arranging a purchase.  
Thank you very much in advance for your suggestions.  Happy Holidays!
Best Regards,
William