The following site has twelve 1977 reviews of Star Wars: [...ok really only 3-5 are readable... as many are unavailable due to copyright... but with the article and author maybe a different copy can be found.]
[search engine] "site:unz.org "star wars""
The Current Cinema (2 Reviews) by Penelope Gilliatt, pp. 69-71
Galaxy Crisis
The New Yorker, June 13, 1977
On Films: Innocences (3 Reviews) by Stanley Kauffmann, p. 22
Star Wars, by George Lucas, ...
The New Republic, June 18, 1977
Films (Review) by Robert Hatch, p. 794
Star Wars, by George Lucas
The Nation, June 25, 1977
"Feel Good" Film (3 Reviews) by Judith Crist, pp. 40-41
Star Wars, by George Lucas, ...
The Saturday Review, July 9, 1977
All-Star (Wars) Escape Extravaganza (Review) by Mavis Lyons, p. 23
Star Wars, by George Lucas
In These Times, July 13, 1977
Film: The Perfect Movie (Review) by David Brudnoy, p. 839
Star Wars, by George Lucas
The National Review, July 22, 1977
Review Star Wars, by George Lucas --- by John J. Pierce,, p. 46
Reason, August 1977
The Current Cinema (3 Reviews) by Pauline Kael, pp. 123-132
Contrasts
The New Yorker, September 26, 1977
Films: Star Wars (Review) by Baird Searles, pp. 61-63
Star Wars, by George Lucas
The Magazine of Fantasy and Science Fiction, October 1977
Films: Star Wars II (Review) by Baird Searles, pp. 98-100
Star Wars, by George Lucas
The Magazine of Fantasy and Science Fiction, November 1977
Films: 3, 2, 1, Rip Off! (Review) by Michael Moorcock, p. 857
Star Wars, by George Lucas
The New Statesman, December 16, 1977
Films: The Things from Outer Space (6 Reviews) by John Coleman, p. 856
Star Wars, by George Lucas, ...
The New Statesman, December 16, 1977
The Revenge of the Empire (4 Reviews) by Algis Budrys, pp. 59-76
THX 1138, by George Lucas, ...
Amazing Science Fiction Stories, March 1984
Movies: Peak Condition (3 Reviews) by David Denby, pp. 55-56
Dante's Peak, by Roger Donaldson, ...
New York Magazine, February 17, 1997
Doubt you'll see another SW review with 'Iteinerant Cowpunch' ever again.
Poking around there are possibly other interesting reviews to find elsewhere unfortuantely. Here's one for maybe the novelization from Feb of 77!
The Reference Library (6 Reviews) by Lester del Rey, pp. 166-170
Gateway, by Frederik Pohl, ...
Analog/Astounding Science Fiction, February 1977