Polarizing lens

I have a ring that has one gray lens in it. This lens came on a Comp C4 I bought, I didn't realize it was half the setup for a polarizing filter. I bought the other half from Aimpoint a few years back. It is rubber with a lens and pushes in the rear of the scope and you turn it to set the darkness (really nice if the sun is directly on the target).
   The front lens is very scratched up and distorts the dot. My question is: does any company make replacement lenses to fit in this ring? I will call Aimpoint today and ask them, but when I got the rear lens they said they don't make the rear anymore so I assumed that goes for the front lens also. 
  Do I need this setup...... I like it because during the sunny times it is easier on my eye and keeps the dot small and perfectly round.
  Thanks in advance for any help, Stan

Polarizing filter are fairly popular in the photography world, It potentially could be a standard filter size or maybe easily adapt one with a stepping ring.

Thanks, I'll search in some camera shops around here.
Stan

You arnent going to be happy at all.. 

The scopes dont have the exact size of the front lens. 

Also, there are a good number of options sold for scopes as it already is. 

However for PHOTOGRAPHY purposes a polarizing lens doesnt make things darker..   it controls reflections and overall color of leaves and grass.  Circular polarizers and non circular polarizing filters. 

the circular, or CPL, you can twist to adjust how things look.  non circlular, its one setting only. 

https://www.amazon.com/Vortex-Optics-Killflash-Anti-Reflection-Devices/dp/B003JP8GMW?th=1