According to the historians of the Order of Hermes, the mechanical knowledge of Hero of Alexandria is a lost Ancient Magic, no longer practiced by living folk. It's fortunate that no Hermetic magus has said this to an Islamic wizard, for the only possible response would be gales of laughter. Mechanica are indeed a subject of active study in the Islamic world, albeit a somewhat minor one, and the Banu Musa (Sons of Moses) are at the forefront of the study of this art from their home in Baghdad, where their ability to create Magical devices without use of taqa or spirits adds yet more wonder and beauty to the City of Magic.
The Banu Musa take their name from their founders, a group of three brothers employed by the Caliph al-Ma'mun. They began as translators of Greek texts into Arabic, but also developed a reputation as mathematicians, mechanicians and teachers, and they left several books on astronomy and on the ingenious devices they had developed. After their death, however, many of their students and followers compiled their workws and continued to build on them, taking the collective name of their teachers for their group. Like many hedge traditions, the Banu Musa are bound together by shared knowledge rather than any kind of society; the Islamic mechanicians are most commonly found in Baghdad, but others have taken their learning and found posts throughout the Mythic Middle East. Unless employed by a wealthy patron, however, it is often difficult for them to fund their work, so many Banu Musa have only a couple of magical devices and earn their living through mundane means, such as teaching or engineering.
Banu Musa Characters: Banu Musa characters are normally Companion-level. The majority of Islamic mechanicians are unGifted, (NB: I am houseruling that there is no reason Mechanica of Heron should require the Gift or be impossible to Initiate. Ancient Magic predates the Initiation rules) and learn the ability Mechanica of Heron through an Initiation at the feet of a senior Banu Musa. The Virtue of Natural Magician (HMRE 83), applicable to Mechanica of Heron, is also normally Initiated; some rumors even indicate that the Banu Musa may have access to an equivalent of Hermetic Astrological Divination, but this remains unconfirmed and may instead indicate a sahir who has learned Mechanica on the side.
Gifted Banu Musa are a form of Learned Magician. A Gifted Banu Musa may open a student's Gift, granting them access to the six abilities of the Learned Magician, plus Mechanica of Heron and Natural Magician. Banu Musa rely on principles of natural magic, such as astrological influences, rather than on entreating supernatural powers, and so the Learned Magician's Warping is inappropriate for them. Instead, Banu Musa gain an eccentric personality trait of their player's choice at +1 upon gaining their first Warping point, and it continues to grow in accordance with their Warping Score. Examples may be curiosity, paranoia, or delusions; each Banu Musa's madness comes upon him in its own way. At +3, this is equivalent to a Minor Personality Trait, and at +6 a Major one. At +10, the madness is so severe that the Banu Musa becomes unplayable as a character.
Uncorrupted Mechanica of Heron texts can be found in the Mythic Middle East, even in Arabic (these are mostly written by later Banu Musa and not translations of the Greek texts), though they are not very common. With troupe permission, any Gifted character from the region with access to Arcane and Academic Abilities may take the Virtue.
Sidebar: Mechanica and the Suhhar Suleyman While the original Banu Musa began as students at the House of Wisdom, sahirs by and large view mechanica as an interesting magical curiosity rather than a serious subject of study. Some eccentric sahirs have initiated the Mechanica, but it's generally not seen as worth the Ordeal flaws. Mechanica cannot, of course, be used to power the Solomonic Arts, and generally have very limited synergy with them.
EDIT: Formalized the rules for Gifted Banu Musa.