Updated 1/8/05
Curt Swan and ?? from "A Zoo For Sale" in Superboy 5 December 1949
Many of the earliest were inked by John Fischetti (1916-80) who had worked with Curt on Tommy Tomorrow, stories for Stange Adventures and Star Spangled War Stories in the late 1940's and early 50's. Fischetti went on to be a famous editorial cartoonist. An editorial cartoon award is named after him.
Curt Swan and John Fischetti
from "Tommy Tomorrow Movie Hero" in Action 149
Curt and John Fischetti drew the very first Superbaby story in Superboy #8 (June 1950). This story was written by Bill Finger.
The classic Swan/Fischetti Superboy features, big 50's hair and a bunched up cape around Superboy's neck as in this story from Superboy 22.
Curt Swan and John Fischetti in Superboy 22, October 1952 "Superboy and the Sleeping Beauty" by Ed Herron
Sy Barry was National's "go-to" inker in the early fifties. His style was the house style of the company. Everybody was told to emulate his slick, clean line. He inked Swan's work between 1952 and 1955. This is from "Krypto the Superdog" in Adventure 210, March 1955, written by Otto Binder.
Ray Burnley (1902-64) was better known for inking almost of all of Curt's Jimmy Olsen stories in the Fifties, but he did do a few Superboy stories, including fittingly "A Visit From Superman's Pal" in Superboy 55 from March 1957. He may have inked several of Ed Dobrotka's late 40's Adventure covers as well.

Bruno Premiani (1924-?) , later famous for his work on the Doom Patrol, made a rare appearance inking "The Rip Van Winkle of Smallville" from Adventure 208 in January 1955.

Stan Kaye (1916-67) primarily inked Wayne Boring, but he did do a lot of Curt Swan's covers and a number of Superboy stories from 1955 to 1960.
Curt Swan and Stan Kaye
from Superboy 47 March 1956 "Clark Kent's Best Pal" by Otto Binder
John Forte (1918-1966), best known for his work on the Legion of Super Heroes, occasionally inked Curt's work, as shown here on "Superboy Meets Supergirl" from Superboy 80 from April 1960.
George Klein (d. 1969) inked most of Curt's Superboy stories in the 1960's. His inking is often considered the definitive version for fans who grew up during that period, much the same way as Ray Burnley's is considered for fans who grew up in the 50's and Murphy Anderson's is for fans from the 70's. George's work is distinguished by his high foreheads and his use of crosshatching and ink dribbles when shading backgrounds. He probably replaced Sy Barry as Swan's regular Superboy inker in 1955.
Swan/ Klein? Superboy 43 Sept 55 "The Super Farmer of Smallville" by Otto Binder
Curt Swan and George Klein,
Superboy 118 Jan 1965
"The Boy Who Unmasked Superboy"
by Leo Dorfman