Could try trekwood.com and just search for your "year". They seem to have the parts (most of the time). Good luck!
2015 F350 DRW, 2015 Sequoia SQ38HRL, G614's, Titan Disk Brakes, Trail-Air Flex Air pin box, SRE4000 w/ X-brace, Heavy Duty Shackle Straps w/ Wet Bolts & New Springs.. Now I am done for awhile.
Last Sept I replaced the fabric on the dinette & kitchen slide toppers & found 2 tucked in the slide seal on top of the kitchen slide apparently dropped there during construction. Might be worth a look!
Danny & Linda
Former '13 FB owner