Great job on that mold and very good thinking with the cabin filter, having dealt with a similar issue, if you don't have the 1z product around, and you have a smelly AC system, I take the top off of Lysol, attach a tip that accepts a tube and soak the vents really well, aka "liberally" once I have made sure I got a good bit of coverage throughout the tract by way of gravity, I let it sit for about 15 mins, and I tape a microfiber or paper towel over each vent(this is to trap any lysol or debris I flush out), fire up the car, and locate the fresh air vent, most times its under the windshield wiper cowl, or on the outer most places of the firewall, if you turn the fan on full speed without the recirculate on you should be able to find it by hearing quickly, from there I spray the lysol directly into the fresh air vent, there is enough suction here to pull the lysol in and you get a very fine mist coming in and not liquid shooting out of the vents, give it a few minutes, and usually you have one great smelling, deodorized a/c system for just a few dollars in lysol.
