I read thisd post this morning before work and meant to reply...
A NEW BG - awesome!!!
Now to add life to it - make sure that none of the lamp enclosures rub on the glass - give these a light sand back by 1mm or so - also the raised partical board enclosures - these are sometimes right on the BG and will gradually rub to give wear spots over time - again sand off but then add a coat of primer to make white again.
The off white LED's are a pretty new product, slightly more expensive, but not a true "blue "light like standard LED's.
The colours in the BG will absorb the various colours that make up light, which gives the inks their colours. Problem is that because LED"s are a TRUE white, some of this isnt absorbed and so they can pierce through like beacons. Sanding the tops works to an extent as it diffuses the light from a pin point to a wider scope, but it wont take away the true blue white and so the "blue"will punch through.
Off white LED's should eliminate this. There now is a range of products including acrylic and vinyl that is designed for true white LED's - everything before it is for an incandescent light and so a yellowish off white - your BG will not have the right inks for true white
