Shell Programming and Scripting

Well, as we don't have an idea how your directory structure looks like, we can't tell how many files will be found below that starting dir. You may want to add the -prune action. Also, the -mtime +2 (older than now - (48h+)) is depending on the time you issue the command; it will yield different results on Monday or on Tuesday, and if issued at 10:00h in the morning or later at night.
The grep will grep filenames sa1 till sa9, but not sa10, sa15, or sa17. Use [1-9][1-9] for a two digit wildcard.
And, finally, you read filenames in the while loop, but you don't use them as a parameter for your sar.sh script; unless you are using the f variable in the script, all the filename a thrown to the bin, making the earlier commands redundant.

I have sorted this out using the -exec function of the find command,
I needed to run the sar -uf command on each individual file in the /var/adm/sa directory

and using grep sa[1-9] does grep for two digits or more as the [1-9] for grep is a wildcard for all numbers not just the ones listed

Sorry for my sloppy wording; you are right, it will grep sa17, but it will grep sa1A as well, should it exist.