That's intentional.
1) Do you have ANY idea what kinda sh**storm would happen with Valve if I made golden wrenches ACTUALLY GOLDEN? The whole reason they made stuff invisible was so people couldn't put exclusive items on at will. So it will stay a normal wrench.
2) It's a material override, which I am not going to figure out.
Don't try to do it. Valve will eat you.
So will voogru.
I'd be scared of voogru more.
Such limitations make me wish EHG or mecha would tell me the workaround they use on their servers.