Alright I have made a lot of progress. First, PowerBook to Mac Plus transfers seem fine. I can send text files and such, but there may be a problem with more complex file (programs see below).
The other thing I did is successfully modify Apache on my modern Mac so that I can exchange files between it and the powerbook. Here is how to do that:
https://coolestguidesontheplanet.com/get-apache-mysql-php-and-phpmyadmin-working-on-macos-sierra/
If you do this PM me, as there are a few modifications that are needed.
So, what are the problems.
a) Often with IE 5.0, or Classilla, I cannot get to websites to get classic software to transfer to the Plus because the browser and site do not share an encryption algorithm. That is OK, as some I can get to. The problem is that most come through as .hqx files. I have tried to extract them, but never have been successful. This is using programs such as stuffit from that same era on the PowerBook. They usually come out as several .dsk files. I have even sent the compressed file to the Plus and tried to see if I could extract it there, but I do not have anything to extract it with.
b) I have a similar experience when I use my modern Mac. The decompressed files are .dsk files and will not run on the PowerBook, or, the Plus. It does not matter whether I decompress them on the modern Mac or the PowerBook. There must be something fundamentally incorrect in what I am doing. So how do people get these classic programs to decompress and work?
steve