What is the original film then?
There is no original film. This receipt is from the Maco company and made before in 2002 in the Efke plant. In that time mentioned Maco PO100C.
Now the production is done by (Agfa) Gevaert and is fitted into the Rollei brand as Retro 100 Tonal.
An orthopan film can have a higher resolution then a panchromatic film, a technique from X-ray, so maybe due to X-ray experience Rollei-Maco is able to specify this kind of film.

In that time there was a (German) article about this film in S/W Magazin.
A comparision between Acros 100 and Retro 100 Tonal/PO100C.

It's still available on the internet:
http://www.schwarzweiss-magazin.de/s..._wollstein.htm
Ungleiche Brüder
Orthopanchromatische Filme:
MACO PO 100c und Fuji Neopan 100 Acros

From the article:
Es war also keine große Überraschung, dass beim MACO PO 100c das Korn eine Spur grober war als beim Fuji Neopan 100 Acros. Darüber hinaus war es beim PO 100c scharf akzentuiert und beim Acros leicht verwaschen. Im Gesamteindruck wirkten daher bei feinem bis sehr feinem Korn bei beiden Filmen die Aufnahmen auf dem PO 100c schärfer, die auf dem Acros etwas weniger körnig.

But in this new (Gevaert) production there could be some differences with the former (Efke) production.

Anyhow this film has on many points different specifications so that you have to try yourself it's worthwhile to use it or not.