Hello again Oldairhead,
checked the distaffer example on hand here. serial begins 66F----. she has three license stickers. the earliest is from the city of Hawthorne, California. this is only ~12-14miles south of the address for I. Martin Imports, so a good possibility she came from them as well.
on the sheet from Martin they state that "Lygie has been enjoyed by American cyclists for over seventeen years" but as the material is undated we don't know seventeen years from when.
confusion regarding model number for your example -
they show a grainy picture of a Lygie Professionale fitted with Campag brakes and give the model number 912M/912L. the brakes mean it cannot be earlier than 1969.
on another page they have a price list for whole bicycles and list the Lygie Professionale as model number 112W for one equipped with Weinmann brakes, 112C for a model fitted with Campag brakes and model 112LW for the women's model.
they mention the professionale is available all chrome.
prices -
model 112W: wholesale 275.00, retail 395.00
model 112C: wholesale 335.00, retail 460.00
am thinking this must be ~1974.