Sorry, tail part is in wrong direction, it should be like it is in "posizione 2".
I found one number 15 - 7500 20, normal number system for B-17.
Freddy, You have map with crashes in area. I'm sure that this tail belong to 42-31749. In same area where we found part of tail, in time of WW2 Partisans and than after war, wood workers have found a lot of part of tail and one body.....
About Klobucar: He research crashed planes in area of Gorski Kotar. Probably he gave You list with all planes that crashed in G.Kotar and in area near G.Kotar....
Hi Rado, thank you very much for your precious information. Unfortunately, I have no particular map regarding crash places in Croatia and Slovenia, instead I have a Yucrashes excel file version that I corrected and updated with regard to some particular cases. I try to keep it updated whenever I happen to find new information about the Slovenian and Croatian crashes. This, because my research area adjoins yours and I'd like to have a general overview, as complete as possible, of the situation.
You're right about Josip Klobucar. He gave me a lot of information about his researches in past. He contacted me a few years ago because he was looking for news on a B-17 that he believed been shot down in Croatia but, instead, had crashed in the Udine area. Unfortunately the MACR was not available on Fold3and so I sent him a scanned copy of the document that I had in paper format.
With respect to that part of tail, my doubts were due to the different angle of the initial edge of the deice boot. Anyway I looked at a lot of pictures of B-17 tails and noticed that the angle is not the same on all B-17's, with no apparent relation to the type of model or manufacturer.
I couldn't even find references to the existence of two or more different types of deicer.
At this point we can be sure it's really a piece of B-17 and that is, almost certainly, that one I've shown in position B.
The attached photo, shows the tail of a B-17 F (The famous B-17F-5-BO - S/N 41-24406 - "All American III" of the 97th Bg, 414th Bs, rammed by a Bf-109 in Tunisia.) and the deice boot looks exactly like yours.