To be honest with you nothing is ever so black and white.. for instance take your drug example.. we can all agree that cocaine is a drug and is illegal correct?

but cocaine is also still used in medicine as an anesthetic and because of its vaso-constrictive quality it may reduce blood loss so it is killing two birds with one stone.. of course it is that same vaso-constrictive quality that leads people to have cardiac vasospasm and sudden death..
thus we can conclude that it has both good and bad qualities.. in the public hand it is an illegal drug leading to death.. in medicine, it is a drug that can save lives.. I don't know how that reconciles with the sale of instruments, when I wrote the above I certainly did state it was my opinion and I AM NOT A SCHOLAR... I just don't think things are as black and white as they appear, so when you post here the opinions will be varied, but I believe a brother above has given you an ask the scholar site which insha'Allah will guide you to the appropriate thing to do..