ClarisWorks used templates (.cws) to quickly produce documents (.cwk) based on the same settings and properties. This was a standard workflow in ClarisWorks and not actual conversion. It is unlikely you can reproduce this using any other software, so the original one remains your only choice.
Convert ClarisWorks template file to ClarisWorks document file.
We found one software available in the database for this conversion.
Apple macOS / Mac OS X software - convert cws to cwk on OS X
Old Office suite mainly for Mac
Convert from cws file format
The table with program actions contains information about what each program is capable of doing with their files. This may be a good pointer for further searches for certain file conversions and help you find the converter you are looking for if our search result is insufficient for you. However, it is far from perfect and may sometimes show results which are not really usable because of the nature of the software handles the files. So a conversion that appears as possible, just because of matched actions, may in fact not be possible.