Rudolf Gronau in Brunswick merely retailed this rifle. Gronau opened his gunshop in 1930. The shop existed at least to the 1970s as “Waffen-Gronau” at Schlosspassage, Braunschweig, but was owned by Werner Dollega then. I still remember that shop as I sometimes bought a box of 22 lrs there. At that time, the 1960s, they had a S&W triple lock in .455 Webley in their window. But I could not afford their DMark 375.- , about $ 95.- asking price then.
The barrel is made of R7L grade steel from Röchling’s steelworks at Völklingen by Louis Kelber, a well known Suhl barrelmaker, script Z like mark. The rifle shows the 1940 – 45 German proofmarks. The “pick and sole” mark is of the Suhl proofhouse. The script Kv mark is found on many Suhl rifles, but not identified. Funk used , as usual then, a Gewehr 98 action left over from the WW1 production. The small letters and numbers under the receiver are factory internal worker’s marks from that period, unidentifiable to outsiders even then.The 8 is a Funk assembly number.
The 6.5x68 is not a “Schüler” cartridge. It was developed by RWS and first shown in their 1940 handbook, together with the big brother, the 8x68S. So your March 1941 proofed Funk is probably one of the earliest 6.5x68 rifles existing.