Hello Ray , I do not know exactly how the builings were, but you can see and study the architecture of Ceuta and Melilla, two Spanish cities that are close to Tangiers and have some points in common with Tangiers:
- Both were taken by Portuguese or Spanish at the end of middle ages
-Churches and Cathedrals were constructed this way :
http://commons.wikimedia.org/wiki/File: ... 3%B1a..jpg
http://commons.wikimedia.org/wiki/File: ... elilla.jpg
So in my opinion in Tangiers at the end of XVII Century there would be a governor villa,built in a "Iberian European" Late Renaissance fashion, Some port defenses like those in Ceuta and Melilla , defensive "Castillos" or castles, barracks, Muslim district and Christian district.
So , answering your question, i would mix both, european and north african architecture mixed. If i were you, i would check "Grand Manner" scenery and go for Spanish buildings ie. a meditherranean church, a couple of villas and some muslims adobe houses are a good starting point
and check current photos of Oran, Larache, Ceuta and Melilla for some inspiring XVII century inspiring buildings.
If you have a look at this page, you'll see some surviving North African Fortresses built by Spanish or Portuguese (Spanish controlled them from 1580-1640(1668)
I hope all of this will help you.