Hacker H/I 300 Binocular Microscope

A Hacker Model H/I 300 Microscope, serial # 65268.

2 Eye Pieces 15X
It has 4 Objective lenses, all are marked Hacker W Germany with the following numbers:
4/0,10. 10/0,30; 45/0,65; 100/1,30 Oel,

The Wooden case is original has label on it with
Hertel & Reuss 35 Kassel, Western Germany

Current magnifications 60X ; 150X ; 675X and 1500X
For my application is to view coins it has
Too high magnification. Too small Field of view and too low depth of focus.
At 60X field of view is 3.6 MM and just 0.14 MM at 1500X
Need low 7.5X magnification to see full crown size coin.

According to Gerhardt Optik und Feinmechanik ( GmbH )
Bahnhofstrae 35 D-34311 Naumburg, Hessen, Germany,
the microscope shown in the picture is the binocular Hertel & Reuss model CN-hF-BIN-VK-ZT and about 30 years old. This type is still produced by them today.
The lowest possible eyepiece they have for this microscope is 8x (They also have 5x and 6x eyepieces in our range but these are not suitable for binocular microscopes), and the lowest objective they could supply has a magnification of 3x . They can provide the complete slide holder of the stage .

This is a binocular microscope where you look through two eyepieces and one objective. In a stereoscope, there are two eyepieces combined with two objectives at the same time giving you a three-dimensional picture.

For examining coins they strongly recommend the use of a stereoscope with a magnification of about 10-60x, larger field of view and higher depth of focus.

My current Need

The top plate which mounts the slide is missing.
This stops my left-right motions. Is it possible to get a replacement.
Need suggestion of source of parts even from an old broken microscope. Which may also provide Eyepieces and objectives of lower power.