6686 El Cajon Blvd appears to have been at the point where it merges with Montezuma Rd.  I suspect all of the above was dozed.  The Google Street View at the bottom of the page, taken in November 2022, is as close as I could get to a current shot.

Hard to tell whether this shot, shared by Scott Shaw, is newer or older than the one at the top.  It does advertise "10 Rolled Tacos $1.00" in the front door.

I lived at the Dorchester apartments just down the street from the restaurant.  There was a barber shop on the property too -- Sam Calvano ’69

I believe that the Sombrero Taco Stand was previously The College Barber Shop in the ‘60s, as I used to ride my bike there every other Saturday and get my haircut from Gilbert -- Dennis Crosthswaite ’72

I'm thinking that Mexican restaurant was the one known as Ramon's back in our day -- Joel Dennstedt ’67

(Close, but no burrito for you -- JF)