Colonial", them
John C. Henry couldn't do proper 'historical detailing' if his life depended on it. There are no classical proportions in that piece of crap. In fact, just about all the 'detailing' in it is totally out of proportion, badly combined, grammatically incorrect or just plain ugly.
That said, for historical references it's always best to go to the source:
For true French neoclassical architecture, start with Jules Mansart; his masterpiece the Les Invalides church in Paris gets the detailing right.
By the way, I'm doing a Scottish Baronial style mansion for a client in Fort Lauderdale. Fortunately he had the sense to start with a good source: the Muckross house in Ireland, designed by William Burn.
Marcello