Sword of Fury
I started with the Sword of Fury. I noticed that the slots behind Scourge's fists were just the right size for one of the types of styrene slat I had. So I cast about for an appropriate base weapon, and settled on the knife carried by Jonas Simbacca of the Exo-Squad toy line. I cut the sword to about the right shape, glued on a piece of styrene slat, and painted the whole thing metallic red. Since then, a fan who molds replacement accessories (he started with the Master Sword for Brave Maximus) has created a better looking translucent red Sword of Fury.
Trailer
After Hooper_X complained about toilet paper tubes being too big to make a
trailer for Mini-Scourge, I realized that the M&M Minis tubes piling up at my
home and office (got a display box of 'em with part of a Sam's Club gift
card) were just the right size. I ruined a couple experimenting with ways to
cut the things up for attachment, but I have plenty. :)
Once I had the right shape of cut, I drilled a hole in the bottom and
inserted a round styrene rod to act as a stabilized, resting between the
"heels" of Scourge to keep the trailer from sliding around. I covered the
bottom of the tube with putty in the rough oval shape of the front of
Scourge's trailer (I used my Black Convoy for reference, as big Scourge had
not been released in the U.S. as of Feb 9, 2002). I also glued a small Lego
piece to the top to be the disc launcher, shaping it with a Dremel to more
accurately reflect that weapon (although the scans don't show this detail
work, sigh).
I used putty to build up the undercarriage of the trailer, but then covered
almost all of the putty work with styrene sheets and rods. I added hexagonal
rods along the sides and half-round rods near the top to help define the
sides of the trailer.
The wheels let me use some leftovers from another kitbash. When I turned
Mirage into Starscream, that left me with a spare set of Spychanger wheels.
I cut grooves into some styrene sheets and glued them together around the
axles for a carriage unit, then added putty to let the unit glue to the
underside of the trailer without the smaller wheels being off the ground.
I couldn't get the "m" off the lid completely smoothly, so I used a
Decepticon symbol from reprolabels.com to cover the rough bits. I also took
a piece of foam and glued it into place near the bottom of the tube to seal
it off and let the trailer hold things. Like the Sword of Fury, or M&Ms.
Finally, the trailer's colors are simply black and silver, which made for a
fairly easy paint job.