Of course it's true, I uploaded a disk image of System 0.85 a while back. Basically if you open the Guided Tour disk on a later model Mac, rename the "oldFinder" file to "Finder" and fix the Type/Creator with ResEdit... voila, you have System 0.85. It does have the "Alternate Disk" still present, along with a few other small features.

Download from http://mac.profusehost.net/crosswire/mac.zip, but I should note it only works in Mini vMac 128k or 512k. Later versions will boot it but most likely have some stability issues.

We also had a discussion about this system version in this 68kmla thread.