To the best of my knowledge, Martin has never actually "made" guitar tuning machines. There's never been a factory owned by Martin that churned them out. Instead, Martin has always used tuners made by companies like Grover and Schaller. They often* have the Martin name or logo embossed on them, which might lead one to believe Martin actually made them, but that's not the case. For every set of tuners bearing Martin logos, there are identical sets without the logos. Parts are fully interchangeable.


* (Often, but not always... All three of the Martins I currently own have Schallers with Martin logos, but the mid-'70s D-35 I once owned had standard Grover Rotomatics.)