Mitch,
You can scan a BG and then import it to your computer... once on the screen you have the long and labourious task of completely redrawing it.
It is indeed long and tedious work which im sure Oldpins will agree on.
Ive just spent all morning vectorising paths for my comp to cut stencils for the rounded black lines on a PF.
4 hrs later and 600 cups of tea and im done.. has been a mind numbing exercise though!
You are correct about redrawing being hard... Its alot easier to start with faded art!
my big problem is I need a scanner that can scan that size! and then I need to get someone to print it on glass.
my local signwriter said he is happy to print onto vinal but thats no good on glass.
I'll work it out one day 
You get it printed in REVERSE on clear vinyl... this is then applied to the glass... flip it over and you have a backglass!
You will need to get it double struck though as the colours wash out once lit up otherwise.
Once the clear is in place you apply translucent white over the clear.. then apply your blockout stencil for the hidden numbers "GAME OVER"text etc..
This is how you make a BG with printed vinyl
