John,
Milling fixtures can go a million different ways, and it really depends on what/where you're going to be grabbing on to. I have professional experience but I also have an X3 in my shop.
I'll give you a couple tips, which for me also at least loosely apply for "real" manual mills such as a Bridgeport.
Firstly, for most small tasks, using the z-axis crank to set general height and locking it down, and then using the quill for the plunge cut can give better results on these small mills. The heads typically are not stable enough for true plunge cutting.
When milling, most cuts you make want to be conventional as opposed to climbing (google if not familiar with terms). The reason for this is that these mills have a bit of backlash or slop in the screws, so climbing cuts heaver than even the lightest finish pass will cause the machine to grab and jerk forward, possibly damaging the part or cutter.
Depending on your tang thickness and the amount of material you're talking about removing, you may not need to hold it by the blade besides for maybe a clamp to keep it from resonating. You might be able to just grind the tang square, clamp it in the vise, and then final contour the tang afterwards. I'd really need to see a picture of what's getting clamped and what's getting removed before I could make a real suggestion.
edit: Also, ALWAYS calculate the proper cutter RPM for the diameter of cutter you are using as well as the material you are cutting. Once you've been doing it for a while, you can fudge it, but in the beginning it is drastically important for your sanity, your wallet, and the life of your tools. The calculation you will be interested in is SFM. There is a little play, so once you have a target RPM, you can go up or down a little to cure resonances, etc.
