Generally, I think quest and other "free" types of melee are usually untradable and meant to stay on the account they were acquired on. This is to prevent players from making multiple accounts and doing the quest multiple times to gather a ton of them to trade their main account.
I don't specifically know anything about the black rose melee though.
One thing I do know is that if something was decided to be tradable or untradable it should not be changed later on. They did this before with chainsaw I believe and it was a mess and created way too many complaints.
Well the black rose is from 2011 so it must have been long before then i guess because I remember buying it