[Willem Fick]

I think what you are looking for is something called spray transfer welding. It can be used to build up a surface in small increments.

Do keep in mind however that post welding you can't only machine a small section of the ways and would need to have the ways re-machined in their entirety to retain accuracy. You may then as well forgo the welding and just have the ways and gibbs machined, ground and scraped in.

There are pro's and cons to chroming of ways. I am a stickler for scraping as it provides you with vastly superior lubrication, though it is not as durable as chrome.