So you say the spots were large and not too numerous to count? Velvet can look like a dusting of small dots, coupled with the rapid breathing and other symptoms you mentioned. The copper is the way to treat both anyway, so you should be covered except for the CBB. Is the CBB tolerating the TTM well? Are his symptoms disappearing or getting worse? If it was velvet then I would think the CBB would be dead by now. Pictures would help clear it up of course.
CBB is still in TTM and alive as of this morning (further indication of crypto). Breathing rapidly, but I think same issue as the powder brown, stress made it worse he is due to be transferred again tomorrow. Might give him a FW dip as part of the transfer if he does not improve some by then.