Janis (and everyone):
I received this email this morning and you won't believe it. This is so exciting. Janis, the name he mentions, is in the document you provided. Read on...
Good morning Mr(s) Chard,
My name is Enrico Pedrini, and I write you from Italy (Bologna). I am 29 years old and I am passionate about history of World War II, a collector and I love recover remnants of war with the metal detector on the battlefields.
A few years ago, I recovered (in the landfill of the 8th EVAC hospital in Pietramala (Firenze)) the dog-tag of an American soldier, whose name was Ernest L. Rowell Jr. serial number O-293486.
I knew from the O of the serial number, that it was an officer, but research on the NARA and Footnote not brought me anywhere!
Some time ago, I have tried entering the name of the dog-tag directly on google and to my surprise I found a pdf file from your site, 337th, containing exactly the same name as the dog-tag!
I am almost sure that the dog-tag in my possession belonged to Major Ernest L. Rowell Jr. of Combat Engineers!
I wanted to know if you had other information about him, because apart from the pdf, I have not found any information about him!
Thanks for any help
Enrico Pedrini
Here is my reply:
Dear Enrico:
Wow, what a thrill to receive your great letter.
I went back and re-read the link you embedded, and yes, there can be no question; it is him. How exciting.
BTW, the "O" on his dog-tag is his blood type. This enabled medics to immediately determine the blood-type out in the field, and was stamped on every serviceman's dog-tag. The other letter on lower right is the faith of the man. In his case "protestant".
I can't wait to post your letter on the site, so people will know of your great discovery. Maybe we can find out more information now, thanks to you. Janis (those were her documents), will be so pleased to hear about this.
I look forward to your next letter.
Warmly,
Marion
Ciao Enrico:
Please do not apologize for your English. I can understand you just fine. 
I too have to use translators, and yes, they do a great job, but sometimes are a little "rough"! 
Welcome to our forum. It's a pleasure to have you here.
I am looking forward to coming to Italy some day. I would love to trace my father's footsteps. Plus I would love to go to Sicily and see where my grandparents were born.
Thank you very much, the pleasure is mine!
If I may, I would give you some detail about where I found the dog tag.
The 8th EVAC Hospital of Pietramala was the biggest American field hospital in Italy during WWII.
This photo of Melvin C. Shaffer, shows how it was extended!
I have a vacation home in Pietramala from nearly 18 years, and I know almost everyone (is a small small town in the appenines) .
Some researchers like me and some of the elders and they told me that once the hospital was dismounted, on the hill where I found the dog tag, that are been downloaded 2 trucks per day for 6 months of used equipment of all kinds.
When for the first time I arrived at the landfill, could not believe my eyes, there was broken and not broken glass everywhere. Bottles of beer, coca-cola, parts of drip, parts of plasma bottle, needles, syringes. We found a lot of wonderful things and the area was so extensive that I could not see the beginning and the end!
Unfortunately I'm young and I arrived late, but many hunters have found wonderful material, talking about dozens and dozens of dogtag.
One summer a few years ago I was there with friends and we started a methodical excavation of the main site, I was lying with his head inside a hole I had dug in the ground, when, touching the wall above, the dog-tag is fall in front of my nose!
You can not imagine the surprise and joy at that moment, because after 30 years of excavations, I thought it was impossible to find something so unique, but obviously I was wrong! 
I think that the Major Rowell has lost his dog tag during assembly of the hospital (I do not know if it is a duty of the engineers, you can definitely help me on this) and then unloaded at the landfill at the time of dismantling the hospital .. .
Ps.: it is wonderful that you want to come to Italy to find the footsteps of your father here! Let me know when you think to come!
Your grandparents were Sicilian? The parents of your mother? (if I'm not indiscreet)
Yes, how exciting to find the dog-tag. I can imagine how you felt. After all these years, something like that was still at the site. Wonderful!
You are right; various engineer units WERE responsible for the building of evac hospitals. In fact, I have various reports from my dad's unit, and they have information regarding the building of evacs. I remember one in particular in the Rhone Valley in France.
My mom's parents are from west Sicilian coast. Puma is the last name. My mother was born here along with a few other siblings, but one sister and three brothers were born in Sicily. My grandparents left Sicily and moved to Detroit.
It will probably be quite a while until I make it to Italy, but I am not giving up. 
Thank you for all you do to help preserve the history.