I have serious reservations that [this] is a Gesellenstück (... falsehood deleted), as Bernhard Merkel's trademark is on it. I thumbed thru Schilling makers and did not see one Gerhard Schilling
As I re-iterate, it was merely a quick conjecture of mine, and might very well be wrong. However... the one and well-known Gerhard Schilling, who died only in 2019, the last scion of the Schilling Forge, was born in 1923. If one speculates that the BBF might be his Gesellenstück, he would have assembled and finished it at only 17 years of age.
And those who are familiar with the old crafts system in Germany, will know that apprenticeship could and indeed often would be entered right after the Volksschule, at 14 years of age (in early modern times, even younger). Three years were the minimum for promotion to journeyman.
It is indeed conceivable that old Ernst Schilling, his father who produced many if not most of the forgings for the Suhl area gunsmiths, wanted his son to properly learn a trade or craft (in fact, THIS very trade) as a suitable base, before he would eventually hand over the forge to him. Sounds reasonable.
Also, a BBF from pre-produced unfinished Gesteckteile would be quite a typical demand for a Gesellenstück. Less hassle and quicker to assemble than a Drilling. Even today, such could be a common exam demand.
Carcano