Believed to have been made in Switzerland, this lathe has also appeared in Japan as a slightly different version, the "Avanti". Could the lathe be Japanese? The paperwork with that version (the lathe was listed for sale in Japan) included a chart showing build tolerances with the text is in English and Japanese.
Both versions are typical of the heavier "WW" design (Webster-Whitcombe) watchmakers' lathes as originally developed in American around 1889. In general these lathes had a headstock spindle to accept 8, 10 mm or 12 mm collets with 50 mm (occasionally 70 mm) centre height and a flat-topped 37 mm-wide, 60-degree bevel-edged bed.
One of the strengths of the "WW" design was the ability to interchange accessories between makers and, whilst the Gem's bed was slightly narrower than standard at 33 mm, it was still able to mount the compound slide rest, indexing wheel slide and milling attachment with fly-cutter from a Moseley.
Unusual in being mounted on a substantial cast-iron base with rubber buffer feet, the Gem had both a neat, integrated main-motor mount and a post to carry an "overhead" for driving (as shown in the pictures of the blue-painted example) toolpost-mounted milling and grinding spindles. The back right-hand corner of the tray was machined to provide a collet storage area - though with provision for only 20, when twice as many could easily have been accommodated -  and in the middle of the base a mounting point tapped to hold the flexible stem of a magnifying glass.
If you have a Gem lathe of any type, or literature about the maker, the writer would be very interested to hear from you.