Thanks for the link, though that seems to deal with US residents returning with items from travels overseas rather than visitors (me) bringing the same items over the border. Would I be correct in presuming that the same restrictions still apply?
I believe so. I found another website for you:
http://www.worldtravelguide.net/unit...rica/duty-free
This is not an official site, but it does agree with the 1 liter of alcohol and 100 non-Cuban cigars mentioned in the official CBP site.
The site does specifically mention a prohibition on Cuban-origin cigars, regardless of the country of purchase. A PP poster who mentioned Cuban cigars in his checked luggage is officially a smuggler.