@JNH-83 thanks for that Shapeways suggestion! They look like good candidates, IMO they are also a bit $ for plastic, so I may continue to look for some other alternatives. But I'm happy to have at least 1 good pre-fabricated option here!

@wishbonebrewery, yeah, how is it vented blanks are not more widely available and used?

I suppose we may as well compile a few of the better DIY options in this thread, such as preferred materials, potential preferred BOM vendors, dimensions, etc. A few weeks ago I'd found a good vendor and dimensions BUT I seem to have not noted that (sigh)... I'll post more on DIY options when possible.

Correct me if I'm wrong, but any steel or aluminum with (appropriate sized) vents would be a candidate material right?