Syria, Palestine, and Transjordan:
The main issue as I alluded to is the Syrian/Iraq border, which should have an angle of about 120 degrees, but is actually 140. I suspect it has to do with the way the polar projection works. Some minor surgery on the Euphrates where it hits the border might be in order.
Iraq next. That resource that
argilas gave me will prove invaluable for this country given the massive changes in the land around the Tigris and Euphrates in the last 80 years. Many of the lakes didn't exist or had different shapes, or did exist but were turned into farmland-same with the once-numerous marshes.
One quick note about city names. I've actually checked historical changes for at least many of the bigger ones. Quite often tho what you'll see in these old resources are the British versions, and not the native ones that were likely used back then. There's also translations from non-Roman alphabets too with their inherent inaccuracies. I did use one of the guidebooks to check all the major cities in Spain (they had an awesome map with the city dots scaled to the population), and could find no discrepancies.
Note: imgbb is currently giving me an error when I try to zoom the image.