“Panchos” are “nachos” with more things added, such as beans and guacamole (or sour cream). Some say that panchos also contain a different type of tortilla chip, not simply the triangular kind for dips. The name “pancho” comes from the Mexican fighter Pancho Villa. It is not known which restaurant used the name “pancho” first, but panchos (like nachos) are first cited in the Rio Grande area from at least the early 1970s. Now, however, most all variations of nachos are still called nachos.
 
   
Google Books 
Cooking Texas Style
Tenth Anniversary Edition
by Candy Wagner and Sandra Marquez
Austin: University of Texas Press
1993
Pg. 17:
One popular variation is Panchos (as in Pancho Villa). These are a spiffed-up version with the addition of refried beans and guacamole. And there are many other toppings which can be used.
 
19 December 1976, Valley Morning Star (Harlington, Texas), pg. B11 ad:
HACIENDA RESTAURANT
(...)
NACHOS - PANCHOS

13 April 1980, Washington Post, “Richman on Restaurants,” pg. SM36:
Pueblo Joe’s
4200 Wisconsin Ave. NW.
(...)
For appetizers, this being a somewhat Mexican restaurant, there are tortilla chips covered with cheese and peppers (nachos, $2.25); or beans and cheese with a few dabs of guacamole and green chiles and ground-up bacon (panchos, $2.95).
   
5 October 1984, Chicago Daily Herald, section 6, pg. 4:
We also enjoyed panchos ($4), which might be described as “neat nachos.” Instead of heaping the mild guacamole, cheese, beans and sliced jalapenos atop a pile of chips, each crispy corn tortilla wedge is neatly dolloped and layered with the indredients. Take a bite, and you get a nice combination of soft and crisp, warm and cold.
 
2 July 1989, Washington Post, pg N28:
The nachos are covered with nothing but cheese and salsa, unlike the mod Sante Fe and Texas places that litter them with a dozen ingredients. Panchos are a little more exotic, being nachos with beans and sour cream.