Pete,
If you are using a PC and the source DVD is a single layer DVD (usually less than 4.7 GB) and you have a DVD burner on your computer then you can do it yourself using software available for free.
It's a two step process. First, you'll need to convert the source DVD to an ISO file and second, burn the ISO file onto blank DVDs. Once you have the ISO image, you can burn as many DVDs as needed whenever you need them.
Both steps can be accomplished using the free ImgBurn program available at:
ImgBurn
There are plenty of alternatives. For example you can copy the DVD to an ISO file using LC ISO Creator available at:
Portable Freeware
That's a very simple application that can even run off a thumb drive.
Then you could use WinImg or Small CD-Writer available at:
Small CD-Writer
Small CD-Writer is another portable application that may be run from a thumb drive. There is an English version available.
If you want, I can burn a few of the DVDs, add labels and return them to you.
Thank you. -- Justin