Here is a popular mod now available from Shapeways as I won't be making & painting them myself but it is a proven design with a few hundred sold over the last few years. It is specifically for the AC/DC Premium, Luci and LE - Stern Pinball games. Not suitable for the Pro version. It is a part that looks like a timber block and is available with plain "Timber Grain", or "Hells Bell" lettering.
Ordering: select a colour that suits your painting style.
Painting: simply paint a colour brown of your liking and wipe off the excess with the wrap to achieve that timber look and maybe repeat a second time with a different brown to really achieve that timber grain look.
Assembly: this is one of the easiest mods to install as it has 2 guides to centre the bell block over the alunium block that the swinging bell fastens to and then push down and the clip section simply stop the mod from coming off but can be flexed out to remove the mod.
I am also fine if someone wants to purchase a few and paint them and sell to the general public all painted up and put there margin on it.
Have fun
A product review can be found here:
https://pinballsupernova.wordpress.com/2015/06/03/swinks-acdc-bell-mod/