I don't think D7E1 is going to work here. Holding down Caps Lock on startup just boots into the regular Mac OS. There are two versions of a modified System file that need to be copied across to the "host" Mac OS. One is for 7.1.2 and the other 7.5. As the 7500 needs 7.5.2 as a minimum to boot I can't use either.

Here's two more pics just to wrap things up:

Japanese text input, popup Finder window and column view

Find is disabled (I can't find this extension to enable it)