Making your own reservoir???
 

so i am unable to find a master cylinder reservoir that i liked the look and size of for my bug. i got the crazy idea that i can make one?? i purchased an alum cap with a weld in steel bung somewhere in the 1-1/4" diameter range. just wondering is there any problems with makeing the master out of steel? will the brake fluid over time eat its way through the metal. i know it can be some nasty corrosive stuff.