Here is a tip for restoring recessed panel lines on circular objects such as bombs, missiles, and fuel pods.  I use a K&S tubing cutter (stock No. 296). It holds the part evenly, so all you have to do is close the clamp and turn your object for panel lines that meet up perfectly every time.  Be careful not to use too much pressure or you will cut the plastic in two. The cutter works well for most objects up to a little more than 1″ diameter. For larger scales, this cutter may leave a “furrow,” but using it lightly on the first go-round will create a good guide for the scribing tool of your choice. The cutter is available at most hobby and RC shops. 

Tip submitted by:
Chris PydeeWinnipeg, Manitoba, Canada