What's the difference between todays national socialists, and the national socialists of the 1920's?

It's a lot like the difference between Martin Luther King era black activists and today's BLM members. They use that one same word, and think it lends credibility (or shock value, whichever) to their image.

Unis

The national socialists of the 1920's where nationalists. Those that you're referring to as "todays [sic] national socialists" are more in the realm of international socialists (i.e. communists). That was the difference between the Nazis and Commies back in the 1920's and 1930's that had them hating each other so much. The German communists owed their allegiance to Moscow instead of Berlin and Hitler. The Nazi's despised them for this, despite their nearly identical economic policies (socialism).

Here is a sign they sold in the Washington Holocaust Museum, people I am sure you will agree know what National Socialism is.

So which current political party do they most represent?

The stupid hurts.

Trump is pursuing a radical shrinkage of the federal government that comes close to overthrowing it entirely. The goal of this project: to leave the country with a minuscule government that is basically an appendage to private enterprise.

Now that Trump occupies the Oval Office, he will do all he can to lower taxes, deregulate the business community, and privatize a large number of governmental activities. Like other Republicans, he is eager to make life yet more difficult for America’s economically and otherwise vulnerable citizens. In addition, he has announced his intent to significantly beef up the military.

The systematic gerrymandering of congressional and state legislative districts has played a crucial role in the control effort, enabling the Republicans to put far more elected officials in office than the size of their majorities would justify. The various voter suppression, limitation, and discouragement schemes have helped to further increase the Republican vote in many places.

Gerrymandering and voter suppression often allow elected officials to disregard the wishes and opinions of all but a narrow base of their constituencies. The resulting autonomy frees them to advance party control as well as policies that are favored by only a small part of the population.

Other methods of advancing the party’s control over government are more indirect. These include cutting back funds for the Bureau of the Census and other federal data-gathering programs that implicitly but clearly criticize Republican policies. In years past, members of Congress have already proposed such informational cutbacks, notably those reporting the increases in racial, economic, and other inequalities that could hurt the party politically.

Further initiatives for party control include the intimidation of critics and the barring of access to critical news media. Presidential tweets can distract attention from important events and facts that could interfere with the pursuit of party control. Fake news can have a similar effect, for example by encouraging yet more distrust of the news media and influential political institutions. The recourse to “alternative facts” that seem to legitimize Republican ideology can threaten the country’s reliance on actual facts.

The tenor of your "question" well demonstrates this last point.

BMW and Hugo Boss supported Hitler. Hitler hated communists and social democrats.

the non goverment creation of the ...federal reserve......