Holy moly! Look at http://www.mkepunk.com/ for all your Milwaukee punk-metal-hardcore needs.
From the site:
“MKE Punk offers defunct Milwaukee-area bands a way to share their out-of-print music. If you have stuff you’d like to share let us know…
“Any band, that broke up like 10 years ago, and is no longer around, we want to see those bands release their music, preferably under an open license…”
The “oi” category caught my eye, though I have yet to listen to the demo tape by the oi band Einheriar. Also, I’m pretty sure they are unrelated to the synonymous Viking metal band Einheriar. Although both existed at the same time, the former was from Milwaukee, the latter from Norway. And the names of the bandmates don’t match up either.
(If you’re wondering, Einheriar apparently was a term from Norse mythology that “describes the slain warriors that have gone on to Valhalla and joined Odin‘s table.”)
Haas414: Milwaukee Writ 
This looks pretty cool, I’ll be digging through it for a while.