Thanks for feed back Old Mart. I have considered this, going for a 3/8in leadscrew in saddle slide and cross slide definitely opens up tools readily available. Have to check that tapping the castings 3/8 ACME allows sufficient thread cover, the tapped through hole is very close to the tool post mounting plane. The ML4 is clearly a much lighter item than 7 series, guess Myford had learnt lessons during WW2 period.