I have never seen an Apple Tech document referencing AppleShare server and v.1.0. Everything on their TIL refers to clients or server v.2.0 and up which definitely requires a Mac Plus.
It doesn't surprise me that the iPhone software will see a physically mounted drive and I am only mildly surprised that it will see a mounted network drive where OS X won't. OS X never ceases to amaze me and of course it makes sense that if your system can see a drive then it should be able to share it. Third party software circa 2008 most definitely would make use of that ability, which is why I reference third party software may be able to accomplish the same thing under System 7.6.1. But that was a whole different system running in an era with totally different needs. You may want to upgrade your CC to run 8.1 as it will offer you even more options for similar software to the iPhone remote to translate a mounted AppleShare volume to TCP/IP. I used to use IP Net Router on my PowerBook Duo running 8.1 to set up two different IP addresses on the same Mac. There was a firewall that interacted with the global IP address and then a separate address that handled my internal networking, via AppleTalk. The net result is that any drive mounted on my Duo was accessible by the software router to share through my firewall connection, because all the resources were being handled by the software, without AppleTalk's limitations. OSX was not around then and I certainly didn't use it as you are trying to, but it seems like a good candidate for accessing an AppleTalk volume. Do a Google search for it as I seem to recall several good article about setting up networks this way.