My first job in electronics was installing Central Office equipment for the telephone companies. Part of that involved wiring the equipment to the FRAME in the Frame Room with 52 pair cables. Typically we ran several dozen 52 pair cables on every job and each of every wire was wrapped onto a terminal pin and then soldered using a 100 Watt American Beauty soldering iron. The soldering alone would take over a week. Every job meant soldering up to forty thousand of connections and would literally wear a good size dimple into the tip of the soldering iron. I used a file to file down the tip and removed the dimple and I promptly got my ass chewed for doing so. It was pointed out to me that the tips were solid copper and weren't supposed to filed or ground down but hammered back into shape.
My point is, that if you have good copper tips you should hammer them back into shape and then tin them and not file, grind or polish them.
I used to work for the "Postmaster General's Dept" (PMG) in Oz, who were at that time the Telephone "Company" in this country.
The part i worked in was not phones, though, it was the Radio Section, which looked after both Radio Comms, & the ABC's Radio & TV Broadcasting transmitters.
The standard irons we used were "Scope" brand, which were an "instant heat" type with a carbon element which was pushed against the back of the solid copper unplated screw in tips.
They could run from a (supplied) transformer, or from a 6 v car battery.
It took quite a while with resin cored solder, but, over time, they would develop pitting on the pure copper tips (no "fancypants" plating).
The "fix" of choice was to file them back to shape------ anyone caught hammering them would have been yelled at!
One advantage of the screw in solid copper tips is that anyone with a lathe & some reasonably pure copper rod could make their own tips, including the odd special ones.
The "Scopes" could "box well above their weight" in doing heavy jobs, but for some really big jobs there were usually a couple of big "firesticks".
Get above that, & you were in the realm of plumbers irons, & a blowtorch, or even oxy-acetylene.
I did see quite a few Adcolas at Phone Exchanges,---- as far as I recall, they weren't plated either.
Over the next few years, Wellers started to pop up everywhere, & we were introduced to plated tips &
"Magnastat" temperature control.
Time went by & the PMG morphed into Telecom Australia, but Weller reigned supreme for many years.