Turns out that after the 2nd world war, all western music & anything russian considered decadent was banned in Russia so bootleg record copies were made with the likes of The Beatles & Elvis being popular.
As no proprietry material or machines were available records were made using crude machines often made from modified existing record players to cut 78 rpm groves on discs made from exposed x-ray film, hence 'Bone records'. Apparently the sound was bad & they only lasted a few plays.
Facinating stuff & well worth a Google if you're that way inclined.
