The interchangeable ones of Exa and Exaktas can be used on all Exas and Exaktas although some look weird on some.
For instance: the original prisms for the first Exaktas (VX and Varex IIa) are the plain silver one with the pointy top and the similar looking one with the two leather patches. They sometimes are stamped „Ihagee“ or VX.
The prisms for the later Exaktas (Varex IIb and such), the one with the black plain name plate, are with three leather patches and have a flat front that fits behind the name plate and is on the same level as it.
The first ones are the P1 and P2 on the wrotniak.net site, the later ones are the P3 and P4.
The shown waist level finder in silver ist the first one for the Exakta and Exa 0, also for the Rheinmetall System Exa but that one is engraved with „Rheinmetall“.
The shown WLF H3 is the one for all Exas except the Exa 1C, that one was fully plastic and has a completely black top, the bottom part is silver.
The prism for the Exa 1C is completely black.
All focusing screens are interchangeable, except the ones in the WLF H1 and H2.
For example, I have a fresnel screen from a 1C in a prism P2 in my Exakta VX (US export model).
Imho the plain silver prism P1 is the prettiest but finding one without marks or dents is getting difficult, even over here where they were made.
Also, there are theories that a prism for the Rheinmetall Exa with a stamped „Rheinmetall“ exists (it is shown on the manual) but no such thing has been found by now.
There are other rarities like prisms with unusual lettering for export or small batch productions but that is a thing for the collectors.
I am quite happy using my Exakta and playing with the different types we have in our shop and get from buying them from their mostly first owners.