Edit: using a 25W iron whose tip wasn't heating up properly. Had to use its sides to get the solder to melt, which affected precision.
It's ugly af but it works
I'm a solder soldier
And I'm so sorry for that last part
Now I need to by something that holds everything in place, because what took most time was, well, that.
When optical mice were first becoming popular, I bought one which had a blinking red light very similar to this integrated into the box.
I setup the mouse and it was fine, but I was more excited about the light; I was young and it never occurred to me that this was something that could easily be achieved on one's own. It looked very similar to your device.
I expected it to lose its blinkiness within a day or two. When it didn't, I got some double sided sticky foam and stuck the gizmo to the wall by my desk. I don't remember what happened to it, but it lasted a ridiculous account of time. I'm actually not sure I personally ever took it down, so it's possible that it lasted until I moved out and my parents threw it away.
Anyway, for however long it lasted, it was a novelty and gave me more joy than was reasonable. I hope your new endeavor has results at least as positive.