G7X front lens scratch: tech advice needed!

Hi guys!

After some advice from "people who know": I am a mech-tronic engineer, so I can fix loads of things....but my knowledge of camera optics is basically zero!

I have a G7X, which works fine, but the glass front lens has a 4mm long scratch on the outside.
I guess previous owner rubbed it with something that had a bit of grit on it, maybe?

The scratch is upper right as you look at the screen: it is only in shot when zooming in about 70%, but some lens flare is evident prior to this point.
Now this is not the end of the world, as the camera is intended for Youtube video and a music video, but I would like to rectify it if there is a cheap easy solution.
I have emailed Canon asking if they can supply a replacement part: this would be the best solution, as I have already managed to remove the lens with no issues, and put things back together ok!
I guess that getting someone to polish it out somehow is not a viable option, as the scratch seems a little too deep for that.

My other option is the reason for my reaching out on this forum:
if I can find a suitable glass lens, could I simply replace the scratched one?
This where I need your help!
What is the spec of the glass lens: I know that I'd need to replace it with an identical (or very similar?) spec lens.....but I'm wondering what effect a different one would have?
Would the pictures come out ok, but with an altered focus / zoom?
The front of the camera says "Canon Zoom Lens 4.2x IS". I know what this means.
The other part is a little puzzling to me: "8.8-36.8mm 1:1.8-2.8" Again, I understand what this means: adjustable length and exposure.
But what effect would putting a different lens on the front have on these figures?

I'm guessing that the 8.8 to 36.8mm is basically the distance between the CCD and the actual lens, as you zoom in and out?

When I removed the lens, it seemed to be a plano-convex type, and was approx 24-25mm diameter.
Again, I guess the focal length is critical, but how do I find out the spec of the actual glass lens fitted to the G7X?
Is there some standard spec 25mm lens that several manufacturers use on their compacts?
I see that this is a rabbit hole I'm going down!

Any help much appreciated!
Obviously, the best solution is that Canon sell me a lens and I can fit that: job done!
But experience tells me that it's just not gonna be that easy: I reckon Canon will say " Sorry, the lens is part of the complete lens assembly and cannot be supplied on its own. The cost of the assembly is £450 +VAT and there is a flat rate £450 service charge!!".....or words to that effect! lol!

What can you tell me, guys?

TIA.
G.