Having trouble indentifying OraInst.loc for 4 Oracle_home

Hello,
I have inherited this system. It has 4 Oracle_homes 816 Homes.
drwxr-xr-x 23 oracle oinstall 4096 Oct 9 2001 8.1.6saidev
drwxr-xr-x 23 oracle oinstall 4096 Nov 14 2001 8.1.6saitst
drwxrwxr-x 2 oracle oinstall 4096 Aug 27 14:06 8.1.7tst
drwxr-xr-x 34 oracle oinstall 4096 Aug 27 14:44 8.1.7dev

now according to Hp, the Orainst.loc is located in /var/opt/oracle
and I see 2 orainst.loc files.
1.oraInst.loc.dev
2.oraInst.loc

When I cat these 2 files. This is what I get...
saitst@takdsai:/var/opt/oracle > cat oraInst.loc
inventory_loc=/u01/apps/oracle/oraInventorysaitst
saitst@takdsai:/var/opt/oracle > cat oraInst.loc.dev
inventory_loc=/u01/apps/oracle/oraInventory
inst_group=oinstall

How do I corolate, the 4 (816 Oracle_homes) to these 2 Orainst.loc?

thanks
Jigar