Entire Figure: Chief Torpedo
+ lots of modelling clay
Helmet: modified dollar store figure accessory
Rifle: I think it came with a Robotech figure
Backpack: Sci-Fi 1986 reversed, dremelled and modified

I always thought that the original Flash figure was a little wimpy. He was also one of the potentially interesting and most underused characters in the Marvel comic. I have to admit that I was a little sad when he was killed on Cobra Island