On this subject of smoked salmon I can tell a funny story that goes back 15 years when I was traveling from the U.S. to Montreal many times a year.
I met a tea merchant in Montreal Chinatown (rue Clark) and started buying his teas and bringing them back to the USA. I not only bought lapsang souchang but lychee and various other black teas, all of which were from a tropical area of southwest China. I ended up sharing my tea with my coworkers and they loved it. So one trip I collected around $200 from them to buy tea and bought $100 worth of tea for myself. $300 worth of black tea, total, but it was good high end stuff.
The merchant packed the teas in clear, unmarked and unlabeled ziplock plastic bags after weighing them on a scale. I then paid based on weight.
I never previously had a problem with US Customs, but this trip going back to the U.S. I was stopped, searched and asked if I had anything to declare. Realizing that if I opened the trunk and they saw the teas and they were not declared I would have a problem, I declared them. I then got sent inside with the teas and they ended up being seized because they were unlabeled and because the customs agent said, "for all we know there could be lizard heads in there." He then asked me to identify each of the unlabeled bags and I knew the lychee and lapsang souchang but forgot the others my friends had ordered. That clinched the seizure decision. I was given a seizure notice and the agent said to me, "good thing you didn't lie and declared them or we would have fined you $600."
Anyway that was the last time I tried bringing tea back into the USA or anything other than what I bought at the duty free store. I bought a large quantity of lapsang souchang in part because my father cured salmon with the tea. I was going to give it all to him and keep the lychee for myself.