I don't know what Lindy claimed, but there is this:

On October 20, 1942, the US Alien Property Custodian, under the "Trading With the Enemy Act," seized the shares of the Union Banking Corporation (UBC), of which Prescott Bush was a director and shareholder. The largest shareholder was E. Roland Harriman. (Bush was also the managing partner of Brown Brothers Harriman, a leading Wall Street investment firm.)

The UBC was established to send American capital to Germany to finance the reorganization of its industry under the Nazis. Their leading German partner was the notorious Nazi industrialist Fritz Thyssen, who wrote a book admitting much of this called "I Paid Hitler."

Among the companies financed was the Silesian-American Corporation, which was also managed by Prescott Bush, and by his father-in-law George Herbert Walker, who supplied Dub-a-Ya with his name. The company was vital in supplying coal to the Nazi war industry. It too was seized as a Nazi-front on November 17, 1942. The largest company Bush's UBC helped finance was the German Steel Trust, responsible for between one-third and one-half of Nazi iron and explosives.

Source

It is accurate to state, I believe, that American industrial and banking concerns helped finance the Nazis.

S