busenitz, all of what mancini mentioned are not true and you do not require those documents anymore.
In fact they highly discourage brining in those document during the interview. It seems there have been huge confusions recently due to the way US Embassy in Nepal operates.

Here is copy paste from appointment confirmation letter. (Remember you need to schedule the interview by yourself these days after paying fee. For that you need to make profile)
Documents required during the Interview:
Appointment Confirmation letter;
Original passport valid for at least six months beyond your intended period of stay for travel to
the United States;
DS-160 Confirmation page print out;
One recent 2 x 2 inches (50 mm X 50 mm) sized photograph, colored, without borders, full-face
view directly facing the camera taken within last 06 months against a plain white background;
Original DS- 2019, I- 20 or I- 797, or any other supporting document if applicable.
Applicants are advised to bring only the required documents. Additional documents (such as
letters of invitation, land titles, property valuations, police reports, audits, and documents from
financial institutions) are strongly discouraged.