Connector box cover

I looked here and there for a cover for connector blocks, to extend my light lead. Didn't find one suitable.
It's a bit tall, I've included a shorter top, could probably go smaller if need be, but will do for now.
I had small self tappers available for the strain relief straps, and a centre screw (M3 25mm) to hold it all together. Top and bottom, click together nicely.

Update:
Upon reflection, I have added V4 top, as it might be easier to just use a size 6 3/4 wood screw, that could bite into V4. I've also lowered the overlap lip, so you could scale V4 in the Z direction to make it smaller, up to 50%, and it should still fit on the bottom part without a gap. If you do use the wood screw, make sure it doesn't short the connectors inside. You could just split it to two singles, as there is no real need for them to be attached together.