Thanks Mike! I have no idea on whether this machine ever came with a lint filter. I haven't seen any, and I suspect I am the first one to ever disassemble the tub. Believe it or not, the odor is still there. Very faint, hopefully with a few more test washes the smell will go away completely. I've cleaned or replaced every component water circulated through, not to mention cleaned areas where water never touched.
The song and dance I got from the seller was that they redid the laundry and only had room afterwards for a stacked set. But I am certain, as you, that the clothes must have been coming out stinking and with many black particles of mold and grime. I can only imagine the mold growing in their new front loader now.