An older version of FastReports is available with source code...
https://github.com/FastReports/FreeReport
http://www.fast-report.com/en/download/free-report-download.html
I guess that Sergey had a class to wrap to FastRreports and since I don't use it, I don't know if this sources can be usefull in case of FastReports for (x)Harbour being descontinued....