Actually, that doesn't quite work because the uncompressed value is shortened:

$ ls -l SG_BSGL01_main_460110220000.log
-rw-r--r--   1 52359    staff    394629763 Feb 10 11:54 SG_BSGL01_main
+_460110220000.log
$ ls -l SG_BSGL01_main_460110220000.log.gz
-rwxrwxrwx   1 52359    staff    75011313 Jan 13 15:43 SG_BSGL01_main_
+460110220000.log.gz
$ gzip -l SG_BSGL01_main_460110220000.log.gz
compressed  uncompr. ratio uncompressed_name
 75011313      3486 -57182.0% SG_BSGL01_main_460110220000.log
[download]

How do you know what units the size is in?

js1.