Hi,
My apologies on not getting back sooner, I've been very backed up with work, etc.
As far as 6.0.4--I am sorry to inform you that I cannot get the systems to you. This is Apple's decision, not mine (you can read about this at
http://www.mac512.com). The best bet to get 6.0.4 is to track down the System 7 CD like I did or to pinpoint the System 6 floppies on eBay or elsewhere.
If I ever come across another one of these CDs I'll let you know.
Sorry I couldn't have been of more help here, but the license included with the CD allows me to use it only on my machines (it's a network license, but specifies that it must be used within your own building/network, which would mean the Macs in my basement).
Scott