MrSal,
It sounds like people are missing the clue you gave them.
It sounds to me like the hard drive was previously partitioned into a small 19gB partition and a larger 149gB one. I would guess that, previously, the OS was installed on the big partition and the small one was used for something else - Linux, maybe.
Anyway, when you installed Tiger, it installed itself on the smaller partition.
If you open Disk Utility and click on the 149 gB partition, can you mount it? I'm betting you can and that it still has Panther on it.