Yeah but wouldn't you also need an empty '89 cowl to display inside the vault, plus a separate Keaton head for a figure of Bruce Wayne? I don't think Batman got got dressed inside the vault, it would be a little odd to have the figure displayed just standing in there.
All this talk of the cave with the vault and the computer console is taking me back to the Batcave Command Center from Kenner (the initial release---before all of the awful repaints). I think they originally intended it to come out in the Dark Knight Collection for the first film, but didn't release it until the Batman Returns line. One of the best toy playsets ever, and a great compromise between accuracy and playability (unlike the cool, but way too massive Batman Forever Batcave). Plus it had Wayne Manor, and the Penguin's hideout (clearly inspired by Axis Chemicals).