When I lived down South , I was always going to "ACE-HARDWARE" .!
Down where I lived , in the nuts and bolts section , I was able to find just about any metric or SAE ,fastener known to man .! I have not had to try that up north yet , but down "Yonder' that store always amazed me.!
Who knows , maybe you'll get off easy with a little blue-ing..?
Good luck..!