I have no idea what they used as the base for the detonator. They may have just custom machined it, honestly. I'll ask my contact once he returns from Croatia.
I wish that little flash was it, I bought one years ago to build a Droid caller out of and it's been sitting in the box since. The base is too thich, also. I think parts from the leg flares were used to make the detonator.
Heres a bad pic and I'm not sure how accurate. but if they didn't machine these (or the detonator) out of one piece I think they used parts of them for the flares, detonator and possibly Solo's Jacket. I have the e-cig batteries for the Solo jacket I ordered but I think I am going to try and make some on a lathe from aluminum. I just have to figure out how to use one first (a lathe)
IMO, the greebles in Han's jacket form the top/inset portion of the X-wing pilot leg flares. I don't believe the detonator is related them at all other than being a metal cylinder, obviously. Just my two cents.