Carl Zeiss ’orto’

The Carl Zeiss orto EP, how much sharper is those vs ex the abbe they sell now ( I found several brands copy ) or compared to the TV Delites ?
I had search e-bay for them, but so far nothing.
If I has a 3 meter FL it will be around 500X with a 6 mm and a 1.5 mm pupil, but the FoV will be very tiny under 0.1 degree.
Does that fit faint targets ?
They are Very tight at only 45 degrees.

Where is the focus point located based out from shoulder ?

Is those EP out on the market sometimes, or where to get a 6 mm ?

How to know if they was cleaned correct vs coatings ?
( is coatings tuff or very fragile ? )

I has a Zeiss 2060S bino and few binos will compete on performing at a dark sky.