Differences:
Confirmed -
Prototype has the 'Sunset' aka 'Lost' plastic, and to go with it, 3 additional lights that sit behind the plastic.
Prototype has stainless steel rails/sidebars for the Path of Adventure.
Unconfirmed -
Prototype has no insignia on wings of German plane.
Prototype cabinet does not have Extra Ball button.
Prototype has extra lighting for the arks.
Prototype has different playfield art.
Value - it should have all the same features as the normal game (as well as those mentioned above), plus the rarity factor, so this should make it worth more than the standard IJ, probably $1K to $2K more.
But I don't really know what I am talking about - only been around for six months.
And don't listen to pinnies4me...
Nick has delusions of picking up a cheap pin...HA!!! fat chance
For some one thats been around for only "six months" you seem to do your homework and are quite knowledgeable.
Thanks for the info.....