Citroën sold 1014 cars in the USA in 1964*. Almost all of these would have been DS's.
* According to a 1981 United States Trade Commission report
USTC, Dec 1981
FRONT TURN SIGNALS. The lens in the Lucas front turn signal units changed from clear to amber for 1964 USA models. The lens remained amber from 1964 to 1967 on both DS’s and ID’s in the USA and Canada.
Lucas front turn signal had clear lens until 1963, then amber from 1964-1967
EMISSION CONTROL SYSTEMS. Starting in May of 1964 and continuing for 1965 models, both ID19’s and DS19’s in the USA received a crankcase breather system that was not installed on Euro DS’s. The system was intended to prevent unburned gasses from piston ring leakage from being discharged into the atmosphere via the crankcase ventilation system. Instead, these gasses were ported back into the engine with so they can be burned by combustion. The system consisted of a rubber fume collector mounted on the valve cover, a Positive Crankcase Ventilation (PCV) valve, and a few extra hoses.
California was the first state to require that all new cars be sold with a PCV system. By 1964, most car manufacturers installed PCV devices voluntarily, so they did not have to make a different version of the car for California only. PCV systems quickly became standard equipment on all vehicles in the USA, because it not only reduced emissions, but also improved engine life since the engine oil was less likely to become contaminated with unburned fuel.
Rubber collector for crankcase fumes on valve cover
Special hose to the carburetor to collect gasses
A steel blanking plate was installed on the engine block where the Euro crankcase breather would have been installed. A similar system was installed on later H-Vans, with some of the parts being common. This system is included in both the ID and DS parts books, but since it has no illustrations, it is a bit hard to find.
Euro breather on side of engine block
Blanking plate on USA cars instead of Euro breather
I have no idea if Canadian cars had these parts or not in 1964, but I suspect they did since Canadian DS's were almost identical to USA cars in this era.