Some of the features I have seen that make it hard to replicate a period design is that things like chainstay shape, top tube diameter and other once mass produced bits are not available without paying for retooling.
If you want a "recreation" get a Sachs lugged AlbertoMasi Nuovo Prestige, a reasonable translation to modern dimensions while keeping the original flavor.
The Henry James socketed dropouts on the Masiguy blog site images are not in keeping with the original in look. The fully painted seat tube just visually reads mid 80's KHS or Centurion to me, but I am sure they will sell. And choose a different head tube transfer, many more pleasing graphic designs to choose from in Masi history.
Also, many of the recreations have migrated in geometry, I seriously looked at a DeRosa recreation but the top tube was way too short in my size, when compared to a period piece.
John Jorgensen
Torrance Ca USA