If you go to the top right of this page and click on Find, you can take the menu down to Projects. There is a Germany project that has several resource people listed. You can contact the one or ones that seem appropriate for your search.
Since Casper Beyerly died in Harrisburg, Dauphin, PA in 1794, he may have lived there for a long time after he left Germany for PA.
Sometimes a marriage record will show the names of parents. Do you know what year Casper married Catherine Daw and at what location?