Top idea, but some people who buy the LE models when first released, dont like anymore LEs than what was originally made.
I have always said an extra small run later wouldnt hurt, but my view was always in the minority.
A 40th Anniversary pin for AC/DC would be awesome. Excellent idea ! 
Nothing would change for existing LE owners.
Still only 200 LTBR and still only 300 BIB. This one would be "x of 100 40th Anniversary".
As a BIB LE owner, I would be totally cheesed off if they made more BIB LEs or if some modder faked one.
No, this would be a special release, not to try and bolster sales but to celebrate a succesful career of a great band as well as a succesful pinball title.
I am sure that existing LE owners would want one just as much as a premium or pro owner. If anything, you may see a couple or so LEs on the used market.
