It looks as though these are the first dozen or two dozen test mule proto-type Metallica Pro machines, which they send out to high usage places like Timezone etc to make sure everything is OK, before the real first big production runs occur. (prototype games from Stern never have the yellow tournament buttons in them).

Its also great to see X Men machines still being built n pumping along. Cool photos !

The cabinet colours of the Metallica Pro looks great !