As far as I know, Shareway IP has absolutely no effect on connecting to a X.4+ machine from a machine running MacOS 7-9. Shareway IP works the other way, allowing connection from the newer to the older machine. Open Transport is what works the particular magic mentioned, and not Shareway IP.
What you do seemingly have to do in order to connect from the older machine to a X.4 share is to enter the IP address of the target machine in that little box at the bottom. Merely choosing it in the old way in the Chooser leads to a networking error. Or so it is on all my machines. Even aliases are flaky, but the IP allows consistent connections.
It is odd that entering the IP in your case doesn't do the trick. Router, perchance? Go through a hub?
What you do seemingly have to do in order to connect from the older machine to a X.4 share is to enter the IP address of the target machine in that little box at the bottom. Merely choosing it in the old way in the Chooser leads to a networking error. Or so it is on all my machines. Even aliases are flaky, but the IP allows consistent connections.
It is odd that entering the IP in your case doesn't do the trick. Router, perchance? Go through a hub?