After assembling my new box of Finecast Havocs, I find myself drawn into the trap of wanting four of every field-able Havoc weapon. Since GW has not deigned to release a Havoc box yet with the value of the Space Marine Devastators I have the option of buying four boxes of Havocs (ouch) or converting my own. Cheapness ... uh, I mean creativity! won out.
You can see that they really aren't dramatically different side by side.
The next step was to mark the placement of the holes, based on the original Fincast Havoc.
I still have two more to go, so more improvements should be made. I plan on trying a pistol arm for the next one that should more closely resemble the official autocannon's grip.