Early C. F. Martin guitars were built with a three piece black "ebonized" neck, with a separate headstock, neck, and heel, or a two piece cedar neck with a headstock joined to the one piece neck and heel.  The head and neck were usually joined with a visible "volute" protruding from the back of the headstock joint.
 
After Martin started building with a one piece mahogany neck, the volute remained on Styles 28 and higher, perhaps as a vestigal decorative element, perhaps to strengthen the transition from headstock to neck.



Stauffer c. 1820



 
 
Martin & Coupa Koa
 
 

 
 
Martin & Coupa Spanish
 
 


 
1840's Ivory Fingerboard Spanish Martin

 
 




The earliest necks with slotted headstocks were ebonized, or painted black, and had "ice cream" style heels.



1840's Spanish Style Martin




1896 Martin 0-42




 



 
  
1870's Martin 2 1/2 - 26

 

 

1885 Martin 0-34

 

 
 
1894 Martin 0-42



1896 Martin 4-42