In the main welding voltage is 25 volt plus one volt for every 25 amp so at 125 amp it is 30 volt so 3750 VA so at 230 volt 16.3 amp with no losses, clearly there will be losses and inrush but that will vary welder to welder.
The old oil filled welders had a further problem, forgetting the dangers of the oil its self, the wires inside the welder were not insulated, the oil would rot any insulation, so it was important that the welder is not dropped as if it is the wires can bend an become too close to each other.
The safety cure is to earth, however if you earth, that earth must be able to take the welding current, I have seen many an earth wire melted due to welding, so in the welding bay every earth wire was 35 mm or larger, and the oil filled welding sets could only be used in the welding bay, one because protected with earth cables and two so no one could drop it.
However the modern inverter welders use a higher frequency so give a feeling of welding with DC, clearly not the 25/75 heat split found with DC it is still 50/50 but a very smooth output, they also have a far lower in rush, and they have replaced both the oil and air cooled welders.
The problem is the oil inside the oil cooled welders has to be got rid of using specialist firms, so there are many oil filled welders tucked into corners of buildings as it costs so much to scrap them, if they can gets some one to take one, they are rubbing their hands as saved the money that would need spending to scrap one.
They can today have safe oil in them, however until a sample is tested you don't know if safe oil or old oil, and it costs to get it tested, I know where I worked they were all drained and refilled with a safe oil, but they were not cleaned out, so safe oil all now contaminated.
As to if you can give away one of the old welders I don't know.
