Empennage: Aft fuselage. Straightening horizontal stabilizer attach bars.

The horizontal stabilizer attach bars come with quite an inherent warp that needs to be straightened.  With similar parts in the past, I've simply clamped the parts in the vise and meticulously labored over bending it straight with elbow grease or made use of a hydraulic press.  Neither approach is a fun exercise as they take a lot of time.  The plans have an interesting approach too (the illustration itself is quite entertaining).

However, I recently ran into a different technique that was worth giving a try.  The idea is to use three dowels in the vise then placing the part to straighten in such a way as to "bend it out" straight.

The approach is quick and worked great.  The only two variables to concern oneself with is 1) how much force is necessary (too little and nothing changes, too much and you bend too far) and 2) how much space between subsequent bends.  It's important to have the part thoroughly deburred since it will be subjected to significant bending.  And the use of eye protection and ear protection would be wise, should the forces at play overcome any of the approach's constituents.

Here's a comparison of the results on a flat steel plate (the underside of my back rivet plate).  The top bar is as received from the kit.  The bottom bar, initially curled by the same amount, as straightened using the above technique.