Hi Alan, thank you for your input.
I started this thread by admiting i wasn't sure myself whether this piece was a weapon, specially because of the flat edges, hoping that some member had ever came across this type of object. So i am still prepared for this thing suddenly being identified as a tool of some sort ... for my sadness

.
... This not meaning that all your consideration points couldn't be discussed, each one per se, although the sum of them has a lot of weight

.
Half sockets may be seen in haft weapons ... at least in ancient rustic ones; i have them myself.
Short sockets also occur in similar situations; again i have one myself, and with only one fixation point.
Made of iron instead of steel ... why not ? There are zillions of old weapons, namely of rural production, made of iron; and again i have a couple of those, eventually the same ones quoted above.
Maybe you have a point on the fragile construction, as also on the flat edges but, considering the countless bizarre weapons that were made by village smiths in the old days, that's not totally out of question.
Further i would say that, this thing being a tool, i may totally wrong but, by no means i see it as a dibble-stick or, much less, as a grain gauge. To my igorant eyes, the first one would more logically be roundish and the second would have the necessary gauge marks, not decoration crosses; but what do i know ?
Please take all i said as if i were thinking out loud ... sort of guessing what it can't be, instead of concluding what it can only be.
Thanks again for coming in.
Fernando