Uncovering Willis Werkheiser
One intriguing possibility is that this instrument was begun as a customized Style D prior to their discontinuation in 1917 but not completed until late 1919. This would explain its conformity to most Style D features. But how and why would Mr. Werkheiser have delayed completion for two years or more? In searching for information concerning anyone by the name AWillis Werkheiser@ I pursued several avenues, including consultation with Werkheiser family genealogists. Present-day Werkheisers have done an excellent job of keeping track of their ancestors and my correspondents had access to extensive family trees and several generations of published birth and death records. Their search (and my exploration of the internet) turned up only one Willis Werkheiser, listed in the following obituary as AWillis I.@ rather than AWillis D.@

This obituary for WIllisWerkheiser appeared
in the Easton [PA] Express on February 22, 1968
Might this be the same Willis Werkheiser who built the mandolin? If the builder was a different Willis Werkheiser, then no traces of his existence have appeared. The dates given in the obituary fit the known facts obtained from the former owner of the instrument. According to the obituary and social security records I found on the internet, Willis was born on February 13, 1897 and thus, in late December of 1919, would have been approaching 23. This is a suitable age for someone who has been in the workforce for a few years, especially during the era in question. The obituary also refers to military service during the First War, a point to which I shall return. My source at Martin also reported that Willis left that company around the time of WW II to work in war related industry C something a veteran of the First War might do. The obituary says that Willis worked for Cutler-Hammer, a company extensively involved in defense contracts. The Dictionary of American Fighting Ships, (Vol. A, 1991, Navy Department, Office of the Chief of Naval Operations, Naval History Division, Washington, D.C.), in its list of abbreviations lists AC-H@ as standing for ACutler-Hammer@ and the company makes electrical components of the sort that would have been highly relevant to the war effort in the 1940s. Thus, facts about Willis' later employment, from both the Martin employee who previously owned the instrument and from the obituary, converge.
Collectively, the facts suggest an intriguing scenario. Perhaps Willis, a young Martin employee in 1917, began working in his spare time to build a custom Style D mandolin for himself or someone special, but was interrupted by service in the Army (the US declared war on Germany in April, 1917). Of course, the instrument he began would have conformed to the size of the production instruments of 1917. Upon his return after the war (armistice was Nov. 11, 1919), if this conjecture is correct, he finished work on the already-begun Style D despite that model, and all 9" flat-back mandolins, no longer being in production. Why the difference in middle initial between the obituary and the signature on the instrument? It is common to have multiple middle names. Family members usually don't refer to each other with middle names. Younger family members commonly refer to their elders by relationship (e.g., "grandpa" or "Uncle Willis") and may not even know a person's middle initials. The relative writing the obituary in 1968 merely may have reported an initial for the 71-year-old Willis other than the one he customarily used as a young man a half-century earlier. This simple possibility resolves the discrepancy, and all other facts fit.
If accepted as a Style D, this would be one of the most unusual Martin mandolins in existence. Style Ds are undisputedly the most valuable of all Martin flat-back mandolins because of their beauty and extreme rarity. This would be only the eighth Style D ever made. Because that model was officially discontinued in 1917, it would also be the last. With its inlaid pickguard, this one is probably also the most ornate D made. Thus, this uniquely styled Employee Instrument, with an identified maker, in as-new condition, may be the most noteworthy of the few, highly-prized Martin Style D mandolins ever built.
Confirmation that I had found the right Willis Werkheiser came in an email I received in February of 2003. It reads as follows:
Hello, my name is [J. B.] (husband of Willis Werkheiser's grand-daughter). I stumbled onto your page this morning while looking for other Werkheiser info. You may already know this, but I can confirm that this is the Willis you're looking for. While working for Martin, he made a guitar for my mother-in-law, Viola, and a mandolin for her sister, Elaine.
So, the mystery is solved. Willis made this mandolin for his daughter, Elaine!
Given Willis's age at
the time, his daughter must have been a young child. Willis no doubt hoped
that she would learn to play the instrument when she became old enough to do
so. The condition of the instrument suggests that, although it wasn't
played regularly, it was a highly valued possession that received the excellent
care that such a gift deserves.