I had it custom made from an outfit called OD Cloth. They make reproduction cloth tarps for WWII army vehicles. I had it done in vinyl instead of canvas as would be proper for the period. This is a husband and wife outfit I believe and everything is custom made. Its by far one of the highest quality bits of the trailer and fits perfectly with the tarp bows I made for the trailer. Came with tarp ropes. Can't say enough good things about the tarp. Group was great to work with. Their website is really dated though. Something out of 1995 so its a little confusing to purchase off their website. I think I had to call them to get this done over the phone as they didn't have a specific Bantam T3-C tarp listed. I could be remembering that wrong. I am pretty sure they can make you whatever you need but they specialize in WWII tarps for various military vehicles. If you have a different type of trailer not of this era then this might not be for you. Here is a link to their site:
Contact Info I have for them:
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I bought a vinyl cover for my M416 from them about 25 years ago and we've used it across the SE, SW, and at least one trip to the NE. The cover is still in solid condition considering that it's been exposed to the sun for long periods, kept the M416 covered during rain storms, and coated with dust and road grime. Good to know this business is still in business.