I don't have any special tool kit for working on my trains. Just use some tools I have around the house from when I did car repair work or some electrical work. Mainly a selection of small to medium screwdrivers and some small wrenches or an adjustable wrench.
I have looked at Micro-Mark tools and find the prices to be a bit expensive! I use Craftsman tools or some Snap-on brand tools.
Lee Fritz