We used to have an older linde non inverter machine, they can be used to make nice welds.... not by me, but by someone much more skilled. The newer machines run so much smoother, and instantly make you a better welder. If the price is right I’d say go for it, and try it out. Depending on what your trying to do, It might fit what you need it to do.
Probably great on steel no matter what. If you want to do aluminum you will need to make sure it’s a ac/dc square wave machine. And if it has a frequency knob, all the better. That machine will do more than most guys holding the torch can do.
Plus water cooling and it would be a great old machine. That is if it’s all that and works.