Backed up ALL except iLife '06

I took the time to back up all my media and documents and even 1 or 2 applications, but I forgot that iLife came pre-installed on my Mac mini when I bought it, so I thought those programs would remain.

I checked my package from my mini and found proof of purchase coupons for the "iLife '06 + Mac OS X v10.4" package, but no serial numbers or anything. Is there any way to re-acquire the software without having to purchase all over again? Buying again would be a pricey solution in order to obtain something I already own.

Any ideas? Anyone have any similar situations losing software like this?

And in a more time-consuming line of thought... could I use my recovery discs from Tiger in any way also (perhaps involving partitioning my hard drive)?