Grave slab conceals a secret?

The germanic national museum in nurnberg keeps a brass plate about the size of A4, which actually had to have its place in the cemetery in mainbernheim or in another suitable place. This is the opinion of the members of the "alter friedhof" association, because the plate is dedicated to the memory of michael schober von crailsheim, who worked as a pastor in mainbernheim for 52 years.
Pastor schober died in 1657 at the age of 77 years and left behind his wife maria and his sons andreas and christian, as can be seen from a written record.
Information from nurnberg
At the 5. March this year, pastor gerhard schafer and the chairman of the forderverein georg gurrath visited the museum in nurnberg to learn more about the memorial plaque and how it came to nurnberg. They learned that the plaque had been sold to the national museum in 1900. The production of a copy is only possible under certain conditions, schafer and gurrath learned in the nurnberg museum.
Since no grave of michael schober of crailsheim has been found in mainbernheim so far, the forderverein suspects that the grave cover in front of the cemetery pulpit points to the gravestone. After consultation with the authorities, the forderverein wants to have the gravestone removed in order to perhaps unravel the mystery surrounding pastor schober.
In addition, the chairman georg gurrath announced that two donations of 1000 euro each had been received by the association in the past year. For saturday, 23. March, 10 a.M., a work service was arranged in the cemetery.
At the new elections there were no changes: 16 present unanimously elected georg gurrath as chairman again. His deputy is wolfgang swars, gertrud lutsch manages the treasury, alfred brendle takes care of the documentation, hiltrud reidelbach and peter hartmann are assessors.