Mail Merge won't print
AppleWorks is a quirky and hopelessly outdated product. I am aware that a few people have an extreme fondness for it however.
It should only have taken minutes to import data, but don't do it in AppleWorks - they stopped making it years ago and it is unsupported and non-standard.
I have just taken two AppleWorks databases, - one older and one newer that needed to be combined. I exported them as tab delimited text and then imported them into Excel (You could use Apple Numbers - the modern equivalent to AppleWorks). Because the to db's had different headers, I imported them into two different Excel docs first and moved the columns around so the matched first, them copy each column over to the 'master' excel sheet.
You can either use the basic database tools in Excel, or once your data is combined and in this kind of data form, it is easy to import a .xls, or .csv into a new database program, such as Filemaker.
If you do copy over the data to Excel, any merge function - for label printing etc. has to be done in Word (or at least up to Word 2004). I was thrown by this until I realised you have to do this. Once a merge doc is set up with the right labels, it worked beautifully. Typical MS though it is a wholly unintuitive process.
Copy and importing data should be done with attention to care obviously. Make sure you have your original AW files backed up before you start.