It may just live after all
BTW nice show of class giving honorable mention to the help others provided
If you continue on with the KISS concept wherever you can, consider foregoing the ever popular o-ring channel and opt for a thin clear silicone gasket sheeting. I believe I posted a source here at one time. One less, and really unnecessary, milling operation. This also insures no cross channel leakage like can happen with an o-ring if it is not fully compressed.