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This Spotswood kit is really helpful for 4U builds, but the screws and parts are tiny (frustrating at first):
https://bitcointalk.org/index.php?topic=1731197.0Your first "Spotswood" build will leave you cursing, the second will be much easier. If you are of my age, you will need those reader glasses to handle the tiny screws. But his designs are elegant in some ways.
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I had one client that assembled over 100 of those brackets.

Much respect to that man.
