Converting EXTRATECH:s 42cm Haubitze M.17 to a M.16

Extratechs 42cm Hubite M.17 is an excellent kit, but for the WW1 Modeller it poses one big problem: this is not, strictly speaking a Great War gun: the M.17 never saw actual combat before 1918. Instead, it was used by the Germans in WW2. But by backdating the M.17 it is possible to model the M.16 variant, that indeed was used in WW1.

But how do you go about to backdate Extratechs M.17 into a M.16? What are the differences between these two marks? Well, this table summarizes this:

	The M.17 (i.e. Extratechs kit)	The M.16
Baseplate	6.5 x 5.2 meters	7.5 x 6.2 meters (in 1/72 scale = 100mm x 87mm)
Carriage Sides (X)	Angled, no step	Rounded, step
Shape of Auto-loader (Y)	Angular, hollow	Rounded, solid
Large platform on left carriage side? (Z)	No	Yes
Traverse drive facing (A)	Outward	To the rear
Traverse drive device (B)	Handle	Wheel
Cover of Traverse Mechanism on Carriage (C)	Semi-circle	Round

For full explanation, see picture below:

This means, that in order to backdate the M.17 to a M.16, you have to do the following things:

• A= Make a new, bigger baseplate (100mm x 87mm). Duplicate the same details as on the M.17

• X= Alter the carriage sides

• Y= Alter the shape and details of the auto-loader

• C= Make a new cover for the traverse mechanism

• A&B= Substitute the wheel on the traverse mechanism for a handle, and alter it's facing. (You will probably be forced to make a whole new traverse mechanism. It is tricky to fold the PE properly.)

• Z= Put a large platform below the traverse cover mechanism.

Below you can find pictures from my own trials and tribulations, converting the M.17 to a M.16:

	1. Here you can see most of the kit parts, prior to being altered etc. Notice the shape of the auto-loader and also the shape of the carriage sides and the shape of the traverse mechanism cover on the left carriage side. That is M.17 for you (No parts have been cut free of their pouring stubs yet.)
	2. Here I have cut out a new type M.16 base-plate from plastic card. I have scribed the circular centre base that the gun rested on and rotated with. No details have been added, yet. Notice that the centre base should be placed slightly off-centre, giving ample room for the auto-loader.
	3. Here I have started work on the carraige sides, and the auto-loader. The round thingy with the square orange addition is going to become the new traverse mechanism cover.
	4. Here the carriage sides are nearly completed - much sanding. The new traverse mechanism cover is soon to be fitted. New rivets have been added, using the white glue-method.
	5. Now the carraige sides are completed, as has the base plate - a combination of scribing, adding detail by plastic card and re-using some details from the original kit. Work on modifying the auto-loader is also near completion.
	6. Now the carraige sides have been joined together, the small platform on the right side have been added, and the large, portable platform on the left just completed.
	7. More detail has been added, the auto-loader completed, and the wheel for the traverse mechanism can also be seen - it is a modified Airfix PzKpfw IV wheel.