This issue is a variant of Daredevil (Marvel, 1964 series) #168 [Direct]. There exist further variants.
The on-sale date is the publication date reported in the U. S. Copyright Office filing. By the 1980s, this date would reflect when the "direct-sale" edition of a publication, i. e., the edition sold through most comics-stores, was made available. The newsstand edition generally came out two to four weeks later.
Elektra misspelled "Elecktra" on cover.