This website came up trumps for Milko, and might be good for the gazillion other folk who made or still make machine tools.
Milko was a brand name of the Spanish machine tool maker MANCISIDOR LARRAÑAGA Y CÍA, S.A. who started in 1941. The company appear to be still active 'construcción de maquinas para trabajar los metales', but not using the Milko brand.
In their heyday most industrial manual machine tools laboured flat out round the clock on production work and didn't last long, perhaps 5 years of 3-shift production. Thus there was a large market for replacements and plenty of opportunity for enterprising engineering companies of any type to have a go. In consequence there are many machine tool brands we've never heard of, some of them huge in their time. In terms of volume and value, Myford were tiny compared with Herbert, but Herbert are rarely mentioned today because their extensive range of machine tools were all far too big for hobbyists.
Dave