What's your location? In most places, the cheapest and simplest solution will be to do as porter suggests and find another SCSI equipped older Macintosh to do the transfer to another, safer, location. Even the actual 475 power supply should be readily available from someone here, or on ebay.

In terms of emulators, and exploring Mac disks from a Windows machine, check out the free and paid solutions from http://emulators.com/

You can read Mac disks from Windows/DOS machines with their free Gemulator Explorer. You will need a SCSI equipped PC or SCSI card, with the necessary connectors/converters to mount the 50 pin, low-density internal SCSI connector on the 475's hard disk.

http://emulators.com/download.htm#UTILITIES

This free release is limited to copying a single file at a time from the Mac or Atari disk to your PC's disk.

Click to expand...

I assume there is a paid version.

Once the disk mounts, you should be able to read and write it with their SoftMac or Fusion emulators.

http://emulators.com/download.htm#MACINTOSH