Lampshade???

I need to finish this rehab...I originall thought..rectangle lamp base=retangle lampshade easier said then done.
I can not find a white retangle lampshade locally. Online including shipping it is $45! That is 9x's the amount I paid for the lamp!

Today I came across this picture. rectangle lamp base= drum lampshade??? could it work? This lamp pulled it off...why not mine? Drum Lampshades are easy to come by. I have seen them in walmart & target. I could always return it. Goal this week-finish the darn lamp!