The words that belong in the blanks are:
read, carries, waiver, inn, cliff, Grimm, basses/bases, buss, knight, paired, caries, pared, llama, Starr, night, butt, lama, bee, in, bus, waver, Clif, pie, red, bailed, be, loss, Ann, canvass, grim, scent, venous, star, knew, baled, add, but, maize, ad, Los, oar, or, maze, heroine, new, Venus, cent, pi, canvas, an, heroin
The words come in pairs that sound alike; one of the pairs has an extra letter. How far apart the members of the pair are tell you how to order the letters. For example, MAIZE and MAZE are five blanks apart, so the fifth letter in the message is I. (Actually, the sixth, since the first pair is the one where both members of the pair can fit in the same blank: BASSES/BASES. This was done so that the math would work out!)
0 S basses bases 1 A oar or 2 I paired pared 3 D add ad 4 L llama lama 5 I maize maze 6 K knight night 7 E heroine heroin 8 E bee be 9 R carries caries 10 I bailed baled 11 K knew new 12 S buss bus 13 S loss los 14 O venous Venus 15 N inn in 16 S scent cent 17 F cliff Clif 18 I waiver waver 19 R Starr star 20 S canvass canvas 21 T butt but 22 N Ann an 23 A read red 24 M Grimm grim 25 E pie pi
Eriksson's first name is Leif; therefore the answer is LEAF.
Story restored in 2010 by the archivists of Beginner's Luck, based on the same re-created script used in the puzzle. Thanks to Lance Nathan for providing the story.