First, use the new MTH parts website. https://www.mthpartsandsales.com/shop/search/results
Then when searching using old part numbers- remove the dash!!!
Same website, has wick from the homepage, https://www.mthpartsandsales.com/
Then go to "upgrade kits tools, and products" or this link https://www.mthpartsandsales.c...ts/240?type=products
Bottom of that list is official MTH wick material.
Yes, you can use fiberglass braided rope wick, but do not use cotton based wick.
Last, "Lastly, the protosound 2.0 is not generating the proper sounds. I hear the train chugging and a whistle, but all the extra noises (brakes squealing, freight noises, etc...) are not present."
Reset to factory defaults. There is NOTHING wrong with your "sound box".