Non-Buff Boba Fett
Above is a close-up of the back seam. Unfortunately, the scalps obscure the seam a bit. Also in the scan you will see the remaining backpack piece (which was painted brown) from the vintage Fett - what was leftover after I made the cut. I think you can get a good feel for how it should be when you make the cut. If you're afraid of cutting too much, just cut a little bit at a time.
I basically used the POTF2 Boba Fett from the Boba Fett/IG-88 2-Pack for all parts except the torso. The torso is the top half of the body piece from the vintage Boba Fett, and all parts had to be fairly modified to fit together. The pseudo rocket-firing backpack was cut off the vintage torso and replaced with the green armor piece from the back of the POTF2 figure that holds the backpack. The legs and arms were repositioned for the pose. Lastly, the whole figure (except for the head) was repainted, and his cape was glued on his shoulder. And yes, the arms, legs, and head do move, but the waist does not.
If you want to make your own, I recommend using only the regular POTF2 Fett or the 2-pack one. The Deluxe Fett has a slightly different mold, and I can't guarantee that it will work with the vintage torso.
Lastly, you can also choose from two different color schemes when painting Fett. There is the Empire Strikes Back scheme (pictured above), and the Return of the Jedi scheme (which has the red wrist armor pieces ala the regular POTF2 Fett). I personally prefer the ESB scheme.
For other non-buff figures, see my Non-Buff Greedo, Lando, Rebel Fleet Trooper II, Stormtrooper, and Carbonite Han.