Yes, You can convert a Konvas-2M to Pl mount, but, this is not easy procedure.
From one side, this is very easy, you need unscrew a 3 screws, take away OST-19-144 lens mount and set Arri PL and set screews.
But, I'm camera and optical mechanician and can confirm, You forget a very important procedure - check and adjust of flange focal distance of lens mount.
The precision of set a flange focal distance must be +/- 0.01 mm, and this is too high precision. You will need special mechanical and optical tools, collimator for this.
Any procedure with body and lens mount of camera must be with test and adjust a flange focal distance of camera, focusing screen.
I hope, you will need sharpness images at film, that's why you need do this.
That's why, the procedure of change a lens mount must do a camera mechanisian with experience and special mechanical and optical tools.
Olexandr
olex@a-teleport.com