With 70,000 members posting items they would like to barter with or for, there is a good possibility you can find what you are looking for at U-Exchange. Listings are available from all over the world, and the search feature lets you narrow down your choices by keywords. There is no charge for membership or listings, as advertisers pay to sponsor the site.
Can you make home or vehicle repairs? Do you manufacture pieces that may be needed for repair? Can you grow fruit and vegetables and gather the seeds to sell? Do you sew, knit and repair clothing? Think through what you can do. Many skills that preppers have are taken for granted by others. The skills that you have that seem like common sense to you could keep you and your family fed in hard times.
Business to consumer barter may include things like free merchandise for a customer who is willing to provide sales leads. Person to person barter can include almost anything you can imagine. Auction sites are a good place to find others willing to trade for things you have. Classified ads, online or in print, are another handy way of conducting barter transactions, and so are barter clubs.