Does that look like any polishing you have ever seen? A bit of tarnish/toning, no polishing lines anywhere
This issue was struck in Business Strike (BS), Proof-Like (PL) strike, and Specimen (SP) strike. This could be a PL or SP strike that was circulated (or used as a pocket piece), but it looks more like a circulated BS that has been polished up with silverware polishing paste. I say that due to the reflectivity of the "dings". https://www.coinsandcanada.com/coins-prices.php?coin=1-dollar-1964&
IMO a polishing paste would be revealed by a multitude of hairlines, of which this coin has none. See close ups above
When I was very young, I used my Mom's silverware paste to make my Mercury dime collection look "extra special". Your coin looks "familiar".
I too have polished as a kid many copper nickel, copper and silver coins - thankfully not any of value. Also, I am quite used to specimen PL vs. matte, etc. from the Franklin Mint which cued me in a bit. This IMO does not appear like the polishing that I did on a "gross" sense, but also do not see polishing lines and the lettering is preserved - in order to get that effect, or lack thereof, there would be a halo effect around the lettering. Not to confuse but there is none of that. Also, planchet prep is an interesting phenom in that there can be some real roughness to the flans even when lightly polished PRE-STRIKE & not all of the roughness is struck out...