hmm i may ahve and idea take the left stantion off take all internals/nobs everythings off flip it aroudn so the dent is at the top and then yur fork will work again just an idea not sur eif u can do that to a 40 tho its worth a try...

 The only way to fix this is to take it apart and find in your area someone who polish the aluminum and knows what the hell is doing. Like motorcycle wheels or frames etc.. Polish to mirror look and will never leak any oil.. trust me my LBS is doing that for few years now..

You wanna sell that 40 ?

 no inside of the stantion is grooved etc for certain funtions

 its not a dent its just slight wear and dont know how much

 do u ever service your forks?

 what did you do?