Hi,

I have identified a couple of Fraxinus pseudomorphs from the 3rd-millennium BC Royal Cemetery at Ur (Iraq). It is about to be reported on in a more general paper in the symposium, "ENGAGING CONSERVATION: COLLABORATION ACROSS DISCIPLINES" http://www.penn.museum/loveconservation/  (October 6-8, 2016). I can send images if you write directly.

You could contact Willy Tegel, he has been working on the (mineralised) wood used in Early Medieval weapons and has found Fraxinus the most commonly used species: https://www.researchgate.net/publication/286611478_The_wood_of_Merovingian_weaponry. Unfortunately the only material depicted in the paper is Alnus and of course most of the metal is iron.

Article The wood of Merovingian weaponry

Not sure if this can help you, maybe worth checking.

http://roderic.uv.es/bitstream/handle/10550/37570/2313-7132-1-PB.pdf?sequence=1&isAllowed=y#page=135