Le 345

Lemair Helvetia 345
"I acquired an original copy of the User Instructions for this machine and find that this is a case of a machine that has a model number with no idea what the commercial name was."

User Manual
The cover is identical to those of the Brother 345 which I have seen online (see below) except that it has a gummed label with "Lemair Helvetia" stuck onto it!

Examples
How to use a vintage sewing machine brother 345 - This is of the Brother base design but a really good overview of the machine