Leopard Back Up DVD

i have a 10.5.0 copy of Leopard i purchased the first week it was introduced.
i ripped it to my external harddrive as aback up incase i lose it or it gets broke and scratched.
when installing it on a Macbook it made some grinding and i pulled the disc out with a few scratches on and wouldnt read, nor would it on a G5, tried it on several machines doesnt read the disc.

So my question is...I wanted to create a Single-Layer DVD Back Up of this since the drive in a spare G5 i wanted to slap it on doesnt work with Dual-Layer Discs, and i have read a lot of tutorials on this and dont have access to Tiger or a Tiger OS.
The image is already ripped to my system and i removed all the X11 Tools, Printer and Language Packs as described in a few of them.

However it always spews out an error in Disk Utility, not enough room to copy and ive tried with several media, the disks are good, after wards i burned other apps to them as well.

So is there a fairly easy step by step process to get it work successfully?
Im capable of understanding tech terms and ways to do this, but it seems some of the tutorials leave out some small minor suggestions that might make it easier or they used Tiger to do this.

thanks!