Hello J, This would be an indication of damage caused by water/moisture and shouldn't effect any sort of performance on the case. I should also mention that the case would be out of warranty at this point. The only viable option may be to speak with Cybertron and see if they can assist. Regards, Mychal CMUSA Support Lead
The above is the response I received from submitting a ticket to customer service.
The advice is not helpful for the following reasons: my computer's one-year warranty with Cybertron has expired, and Cybertron did not manufacture the case.
In addition, drawing air through rusty vent holes into the PSU fan does not seem like a good idea. (I just bought a new replacement PSU.)
I am still trying to get an answer as to whether I can purchase a new bottom panel for the case. And if so, how much would it cost, and how difficult would it be to install?