Interesting question! I wasn't familiar with the opera in question, but I can shed some light on its contents, the origins of these contents, as well as the historiography of Zoroastrianism.

As you note, the plot has only the most tenuous connection to history - about the one correct plot element is the geographic location, Bactria (modern Balkh). The names of the "genies" are derived from distorted greek forms of Ahura Mazda/Ohrmazd (Oromasès) and Angra Mainyu/Ahriman (Arimane). The name of the evil sorcerer "Abramane", I suspect is derived from "Abra" as in "Abra kadabra" plus "mane" as in "Arimane".

It's immediately clear to me that the character "Zoroastre" must be based on the figure of Classical (mostly Greek) literature usually known as "pseudo-Zoroaster", who can be roughly summed up as an ancient Persian (or sometimes Magian - the Magoi were a clerical tribe of the Medes) sorcerer-king of Babylon or Bactria who had invented magic. The most likely sources are Pliny's Natural History, Plutarch's Isis and Osiris, and/or Diogenes Laertius, where I'd say Plutarch is the most likely given the geographical location and the inclusion of the battle between good and evil. My acquaintance with these texts is a bit superficial since they are distorted enough to be of marginal to no interest for the study of actual Zoroastrianism - though Plutarch's text does accurately reflect some key doctrines of Zoroastrianism (e.g. Heptad of Amesha Spenta).

For the historiography of Zoroastrianism I will draw on Stausberg and Vevaina's introduction to Wiley-Blackwell Companion to Zoroastrianism. Scholarly work on Zoroastrianism (as opposed to interest in Zoroaster as a mystic or magician, which seems to have persisted from the classical age on) actually begins fairly early, with Thomas Hyde's Historia religionis veterum Persarum published in 1700. Hyde drew mainly on Classical, Islamic and Eastern Christian sources, and also translated an important New Persian source, the "Hundred Chapters". This volume, overall, is however predictably placed in framework of Christian apologetics; however, Hyde had the foresight to realize that there had to be ancient Zoroastrian scriptures waiting to be discovered (i.e., the Avesta) and thus inspired much subsequent scholarship.

The next key figure is Abraham Hyacinthe Anquetil-Duperron, who traveled to India to obtain and translate a large amount of important manuscripts, as well as an attempted translation (the Zend-Avesta of 1771) into French of key Zoroastrian texts based on what he had learned from Zoroastrian priests, which are today mainly useful as an insight into the teachings of 18th-century Zoroastrian clergy. He also documented much of the daily life and rituals of the Parsis.

Philological work continued in the late 18th and early 19th centuries. But the scholar to perhaps eclipse all others in the 19th century would have to be Martin Haug, who realized that the Gathas, were of special importance and composed in a significanly older dialect of Avestan than the so-called "younger Avesta", and argued now typically accepted points - that the Gathas had been composed by Zoroaster himself, and that Zoroaster must have lived before 1000 BC, and not in 550 BC as Parsis generally believed (and which many, to my knowledge, still believe).

However, the one scholar who has to be assigned an absolutely singular importance is Mary Boyce (1920 - 2006), who is to be credited with integrating studies of Zoroastrianism into a coherent subject and study of it as a tradition, and who co-authored a multi-volume set of works on Zoroastrianism in the 1970's and 1980's, as well as the ubiquitous 220-page introductory work Zoroastrians: Their Religious Beliefs and Practices along with Textual Sources for the Study of Zoroastrianism. Stausberg & Vevaina go as far as to call her "the first Western academic who can be qualified as a Zoroastrian scholar per se", in contrast to earlier Orientalist scholars. Her work is really the starting point for all modern studies of Zoroastrianism, and engaged with by virtually every single scholar, even if critically. This paradigm shift is something that can make interacting with Zoroastrian scholarship quite difficult (and why something like the Wiley-Blackwell volume is such a godsend to me when writing answers here) - too often I've found myself stuck between citing Boyce alone or citing Boyce plus engaging with the work of some 130-year old Orientalist and trying to contextualize it! If you read pretty much any, say, Wikipedia article on Zoroastrianism, you'll most likely find that it is almost entirely based on Boyce's standard text.

Let me know if there is something you want elaboration on or if you have follow-up questions!

Sources and further reading: Wiley-Blackwell Companion to Zoroastrianism - Stausberg & Vevaina (Introduction, plus chapter 27, [Intersections with] The Classical World, by Martin L West)

Zoroastrians: Their Religious Beliefs and Practices - Boyce