So I've seen a few way repair threads with various ideas. In industrial fabrication and automotive body welding to avoid warping material we would warm the area gradually, apply a tack weld, and just before the red heat color disappears apply another one, repeating until the space is filled. Does anyone know with any certainty if you could use this technique on hardened ways in place on the lathe and stone grind to finish? It would also leave a hardened repair similar to the ways.
Been covered on PM. More than once.
Short answer is that planing/milling then re-grinding & scraping or at least flaking are the only predictable methods as to time and cost, and not always justifiable, even so.
The more exotic methods are less predictable as to outcomes at any cost, tend to be rudely expensive, hence justified ONLY when the machine-tool is exceptionally valuable, near-as-dammit impossible to replace AND can justify whatever it is expected to produce in revenue.
Gots to keep in mind that labour is never free, so the point can come where it actually makes sense to buy - or even design and
make - a whole NEW machine, outright.
Which happens. Often enough to put a great many USED machines into the market.
If the entity as sold those used machine-tools found it cheaper to buy new than rebuild?
What did they know about what they sold that you do not YET know?
Could be that it could not justify the cost of rebuild?
What you do as to blood, sweat, tears, empty pockets, patience and dedication out of love, curiosity, desperation, or just because you CAN runs on its own decision system.
There is precious little in the way of shortcuts nor ANY "easy magic" to it, though!