The 40mm Single Bofors included in the   deck hardware kit is adequate for most modelers.   But you may want to add one from HR Products.  Here is an example of the mount I got from HR Products on the platform in included in the Dumas kit.

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I was not happy, so I set out to add a little bit more detail.

I removed the wedge shaped foot rests and seats that you were to build according to the Dumas blueprints.  I then turned my attrition to the 40 mm I got from HR Products.

The version of the mount you get from HR Products is a WWII vantage.  Not sure of the MK number though.  I decided to strip a few things off the stock mount.  I removed the motors and the lower platform.   I kept the metal seats, hand cranks (what if the ship lost power?), foot rests and sights.  I decided to mount this on the platform in the Dumas kit, because it was cut to fit the area between the rear breakwater.

Here are the details:

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You can see the hatch used to move 40mm rounds from below to topside.   This hatch was left off in the kit.  Note the vents, NOT doors as described in the kit on the back of the aft breakwater!  Also, the seats are more scale too.

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Ah, yet another view.  Here you can see the fire extinguisher (25 lbs. bottle) mounted on the aft breakwater.  Also, you can see the ladder mounted also.

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Here you can see the shore power cable reel.  I made it from sheet styrene and some wire.... simple but very effective.

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