Hi, Liftin -
Welcome to Apple's Discussions.
Using the Mac to do the conversions -
If you're lucky, your version of MacWrite II came bundled with a usable version of MacLinkPlus, which is a transparent conversion utility. It allows the conversion of text files to/from many different word processor program formats for both Macs and PCs.
To see if you do have it, open one of the files in MacWrite II, then do a Save As (File menu). Check the offerings in the File Format pulldown menu in the Save As window, and if there is a usable one available, select it and then complete the Save As operation.
If you do not have MacLinkPlus, you can purchase it. It is published by Dataviz; the OS 9 version (for OS 9..1 or 9.2.x) is available here -
http://www.dataviz.com/purchase/buy/maclinkplus/mlporderv14.html
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Using the PC to do the conversions -
I don't have a clue how to do that, nor if it is even possible (I don't use PCs). Perhaps someone else with that knowledge will post in with it.