Just get some standard from pinball heaven
standard playfield glass (21 x 43″) **collection only** Part No. 08-7028-T”
www.pinball.co.uk
Obviously it's not as good, but it will be a million times better than what you have, I bought some wide body from pinball heaven for the STTNG which also had some scratches.
You could get normal glass from a glazers it's not that difficult once you know the requirements. Search in the field and I think it will pop up.
Although its possible to probably get the glass coated, I suspect its the same coating that used for art framing. I had a massive in size art piece glazed with the same coating, that had no reflection and uv, you can't see the glass at all, but for the life of me can't remember it's exact name. The glazer bored me to death with it and it's spec when I had it done.
(But the result is amazing)
I know pinball call it invisglass but I'm not sure if it has an actual technical name for the spray.
I do know It's not cheap.
My only advice is if you put invisglass on, be prepared to start seeing every fault, imperfection, mark, slightly dirty part underneath it
So it does depend on what you want to achieve, seeing the ball, removing glare because of its location and lighting, showing off the under playfield, but in my opinion the results come with consequences depending on your personality in relation to the condition of the machine.