O.k., this is what I found out.
My first guess was mid to 2nd half 15th c., ca. 1450-70.
This surmise is backed up by the existence of a very similar halberd, Swiss, dated to the second half of the 15th c., and preserved in the
Historisches Museum Berne. I attach scans from Wegeli's well known inventory of 1939. The text mentions that the lower end of the haft has a pointed iron shoe, just like my earliest halberd of ca. 1500. This is a feature which does not occur after 1500.
Please also refer to my thread
http://www.vikingsword.com/vb/showthread.php?t=7450
Congrats once more, 'Nando, you made a fine bargain and did good hafting work as well!
Your new acquisition may well be of Swiss origin.
Various star shaped makers marks similar to that on your item are also to found on these Berne halberds.
Best,
Michael