Quoted By:
Well supposedly it used the Metal Powder item to evolve. So there's that to go by, and to this day it still boosts Ditto's defense, which would be its draw to attach the item, then trade it for the new mon.
I'm guessing if it were finished it would be Steel type, get a stat boost in defense that makes it akin to what Metal Powder made Ditto's or slightly better. Probably a bit of a boost in other stats minus speed probably.
They might have also given it some Steel type attacks so it could be used just as a bulky steel type mon, but with the option to transform.
In the end, it would have been pretty subpar, and they probably made the Pineco line to fill in the bulky steel niche better. I do like the mon's design though, as it's quite creative to make Ditto react like ferrofluid would with a magnet.