I also have often seen this, but usually they are very small brads. What have you got? Finish, 10 penny, railroad spike=:(? I suspect that the up stop rail was positioned at the proper height with the screw/slot thing and then small brads were added as a fail-safe for when the screws loosened over time. I once had an old Chickering that had the rail screwed, nailed, and glued. The felt was long ago worn away but by God the rail stayed put. Paul E. Dempsey, RPT Piano Technician Sr. Marshall University Huntington, WV 304-696-5418 304-617-1149
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