Poor mans 870 shotgun light mount prototyping : or : over-complicating simplicity

For awhile now I've been painfully aware of how handy a powerful light source can be on any firearm you may employ in defense of your self/home. About a year ago I invested in a Streamlight brand TLR-1 tactical weapons light. This was the first dedicated rail mount compact flashlight I've owned and I honestly couldn't be happier.  I have not been happy with the price points of mounts for various platforms that I wish to be able to install the light on so of course....I'll try my hand at making my own.

From the depths of the parts bins I came up with a picatinny rail section (Weaver 61A) that I happen to have a bunch of new in the bag that seem like they will work perfectly for the donor rail section for my little project. My goal was to make a standard magazine tube/barrel clamp mount. I started with a large chunk of aluminum and figured my cut spacing and went ahead and drilled the holes for 1/4" hardware. 

Block drilled for cross bolts but not yet cut in half or profiled for clamping surfaces.

Intended flashlight platform, brain on paper helps from making too many mistakes.

Using a woodruff key cutter I experimented with how the best way to cut the block for the tube reliefs. Needless to say this was a bit of trial and error. Somewhere my measurements migrated a bit and I was about 1/16" off relief spacing. This being the prototype it was mostly proof of concept and the future versions would be vastly improved ie thinner and closer fit. My cost is time and about 20 minutes of machine time and its all metal as opposed to the plastic jobs I'm seeing around. Only bad thing is it does not act as a barrel clamp

Rough clamp in place before test firing

Side view of light clamp.

Just a quick proof of concept project I wanted to knock out, next version should be a lot better.