This great company up the road from us in North Hollywood now has a full series of videos online and FREE for those who wish to learn how to build their own music gear road cases ( or even non music gear for that matter I guess).
http://www.reliablehardware.com/diyroadcasevideos.aspx
They have the full line of hardware that you will need to complete the job also. I have purchased from them directly for a couple guitar amp projects. Earlier this year they were at the NAMM show in Anaheim.
So if you are on a budget and always wanted that cool road case for your Marshall amp head, are handy with the tools, or just want to learn a new skill, check out their website and these videos.