7.62x45

Hello, I’m new to this forum and I hope I posted to the correct place, I am looking for some advice. I “may” want to swap the rear sights on my m27 mosin negant. Has anyone ever swapped a m39 rear sight over to a m27? thanks for any info have a blessed weekend.

Got this a while ago, It is chambered in 7.62x39, not marked '57'. It's in a m14 stock. Sure doesnt look like the work of Bubba. Anyone ever see one like it?