When Helen enters the train to meet John, she is wearing a dark purple lipstick. It's the same in every open shot of that scene. However, on her close-up shots she is wearing a red lipstick.
The list of "undesirables" to be exterminated discovered by Helen doesn't mention the Slavs, who were considered subhumans by the Nazis and have quite substantial populations in many parts of North America.
Price is given Cephalosporin for the infection. Although Cephalosporins were discovered in 1945, they did not go into commercial production in the real world until 1964 and in such a case it would be unlikely that rebels would be able to get hold of them when even penicillin is in short supply. However, as has been demonstrated throughout the series (and in Dick's original book) scientific progress under the Nazi regime has been a lot more rapid, and as such Cephalosporin may be far more common in that world.
It is unlikely that railroad cars only 7.5 meters (24 feet) long would be used to move people to concentration camps. Even before the war, standard railroad freight cars in North America were 40 feet long.