Re: question about radom p35
Pre-War Radoms did not have blued barrels. In my last three years of tracking them I did not come across of the blued version or a documentation supporting it.
As the war went on, the cost cutting measures went into place - just comparing surface finish marks on the early series 1 vs late series 1 will show - it would logically follow that this additional step in production process would be either not employed or abandoned.
Just my guess