Possible Indian Head Cent Proof? Any Thoughts/Comments?

I inherited a bunch of Indian Head cents mostly loose with a couple nicer examples in flips. One of them is this 1903 penny that immediately stood out to me with the sharp rims and appearance. I have never seen such strong contrast between the devices and fields on any of my IHCs. It is a little dirty and was not stored well with exposure to air and clanging and banging against all the other pennies (*cringe*).

I was wondering if it is possibly a proof? The proof early small cents are much trickier to identify as they often look like uncirculated business strikes. Resources and numismatic material are hard to come by online regarding the attribution of proof cents. I know of a couple Indian Head variety websites that do list different dies used, but I was just curious if anyone knows any tell tale signs of a proof cent.

I am aware of the rim differences and the "square lettering" notion but not 100% sure what that describes.

I am not a wishful thinker and I know it is probably not a proof, just want to make sure before I pack it away.

Any thoughts? Thank you!