Pol Stage (petrographic)

[microb]

Hi,

With the following pol stage, I'd like to set up a polarizing microscope, but for those more into petrography, I have a some questions:

1) Is this a legit pol stage slide holder with its large overhang? Are the rounded slide holders required or just preferred or just traditional? I don't have the stage mount just yet to test clearances, which could also quickly answer my question.
2) What are the slits cut into the center disc? This one has two tiny ones (see top view left side of center disk), but others show one large single slit. Is it just to add flexibility to pop it in and out the disk?
3) On the underside, what makes contact with the thin shiny rectangular-shaped sheet (top center circle). That Carl Zeiss guy must have had a reason to spend the extra effort and time to hand craft that additional piece of shiny metal that matches the semi-circle the four screws are centered in.

Thanks.

[PrecisionInstruments]

a) It is a legit Pol rotatable stage. The attachable mechanical stage on top is an accessory mainly used for high magnification adjustments. Placed on the correct microscope, the overhang should not be an issue, in terms of colliding with microscope frame/limb.
b) the cut out’s in the inner disk are produced to give the inner disk spring tension, so that it stays in its recess without movement.
c) I believe this is to rest on an additional machined surface, as the mounting semi-circle do, on different stage mounts