Here's a 2 line graver.
Actualy these are 'Liners' . This one just cuts 2 lines with the width of the tool specified, a #48 (Flat) in this instance.
This is an EC Muller mfg graver. Probably bought it from Mittermeier's in NYC . They used to sell hundreds of different shapes in gravers.
Muller is still in business in NYC. Don't know about Mittermeier
Most if not all the gravers were targeted for the jewelry trade so they were/are not SpaceAge steel. But they'll work just fine on the brass and low carbon and LedLoy steel most M/Ldrs are made of.
They did have some in HS Steel. but no carbide and the like back then.