Converting old Incubi

I won some old Incubi on auction.
How would I go about converting the special weapon Incubi for the current 'dex

Its an awkward pose he's in to replace those hands. Either way you need to replace the weapon with a close combat themed weapon.
The best thing I can suggest is trying to get another Punisher with two hands on the grip (like the guy on the right of the picture) and try shortening the handle until the hands fit where they should be on tghe Shredder weilding Incubi.

Might see if there's a spear handle in my bits box. Could work like that.
Especially since I won 8 more on a low bid