Vertical dropouts question on a rebuild
 

I have an 85 World Sport that I have converted to a fixed. I am having a hard time getting the chain tension correct. I am learning that my drop outs are not technically compatible on this deal. Somewhere I was told that people have filed in a bigger space or used a dremel. The non drive side has extra length but the drive side seems to be closed up. What could I do so I can adjust my chain? Thanks!

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