Thanks, I found "System Picker", which now lets me switch between System Folders. I'm one step closer to the prize. 
My next problem is, I need to boot my machine with 32-bit addressing disabled. OS 7.6 is the first OS to force 32-bit addressing; that's why I'm working with multiple systems in the first place– System 7.5.x allows 24-bit addressing.
However, when I configure 7.5.x this way and restart the machine, it begins to boot 7.5.x, stops, resets, and boots into 7.6 with 32-bit addressing turned on.
So. Is this a hardware issue– a problem with the LC 475, or maybe the physical memory I installed? Or is this a software issue– something that could be fixed with an extension, or an app, or worst case scenario, removing OS 7.6?
My next problem is, I need to boot my machine with 32-bit addressing disabled. OS 7.6 is the first OS to force 32-bit addressing; that's why I'm working with multiple systems in the first place– System 7.5.x allows 24-bit addressing.
However, when I configure 7.5.x this way and restart the machine, it begins to boot 7.5.x, stops, resets, and boots into 7.6 with 32-bit addressing turned on.
So. Is this a hardware issue– a problem with the LC 475, or maybe the physical memory I installed? Or is this a software issue– something that could be fixed with an extension, or an app, or worst case scenario, removing OS 7.6?