It looks to be a tight fit but it should be doable. The Micro is 1.6mm long x .8mm wide and .8mm deep. I looked at my DW ditch light kit and the way it is built it looks like you could just glue the micro to the back of the housing and all will be good. You might have to file a little to make it fit better. Of course insulate it since it is metal you do not need to short out a $2 LED. Since it is built for those little bulbs that are in the package it already has a cavity in the back and it should be made to fit.
I have used the micro's in a rotary beacon and I had plenty of room to spare and it works very well.
Scott
If they are like any other surface mount LED, then yes. I have used the Ulrich Models LEDs for this application in most of my locos. The only advice I can give is that those wires are really tiny to solder. I had trouble at first, but after a few installs, I got it down pretty good.
Will