I found a spare gun for a G1 Topspin at the flea market a few weeks back, and inspiration hit me like a brick wall. Topspin started off as a knock-off of Robot Masters Star Saber picked up at Family Dollar.
The figure fit the bill for Topspin, but a lot had to be done. I'll just walk it through the steps.

Star Saber was a brain master, meaning, he came with a little robot that filled in his torso and became the front of the vehicle mode. This obviously needed to go. The little robot was ripped apart and pieces were taken to make the front of the ship. This was attached to the rest of the figure by an existing extension that previously held the shell of a head. It was attached to the extension by quick steel and a paper clip.
Quick Steel was placed on either side of the chest cavity and a lollipop stick was run down the middle of it. This formed a track for the head to go down, which was attached to the lollipop stick via a femur from a beast war leg(bat optimus primal to be exact.) A ball joint socket was placed in the head, a visor and goatee were molded on, and forks were cut and glued to form his spikes on either side. A piece of fodder and an energon star were fixed to the front of the chest cavity.
The original hands were removed, quicksteel was placed in the gap, holes were drilled, and hands from a Power Rangers Ninja Storm Red Ranger were placed in them.
Femurs from a beast wars figure were taken and butchered to make this guy able to bend at the knees. Pelvis was dremeled to allow better movement.
Base coat of Krylon black then painted with Citadel Hawk Turqoise, a random grey, blood red, and silver.

whew...there you have it. Topspin. I apologize for the long description but I wanted to let you guys know the work that went into him. If you have any comments or criticisms, I'll be more than happy to hear them.