Texas has a couple of different inspections. The annual ( I guess they still have it) state safety inspection that you have to go in and have your vehcle looked over by a licensed state inspector. That can be at a gas station, dealership, or service garage. Level of thoughness varies. Mostly they check your lights, wipers, your tires and check the aim on your lights. The good is that you don't meet many cars on the road with cockeyed headlights like you do in a lot of states.
When I built my T bucket in the 70's I took it down to a local gas station and had him do the safety inspection and then took the receipt to the DMV office to show that it had passed inspection with two photos of the car. That was in 1974 so things are a bit different now than then.
Texas has a pretty straight forward build a vehicle from pieces application.
https://www.txdmv.gov/sites/default/...les/VTR-61.pdf
Very simply documentation is everything there. Bills of sale, receipts from wrecking yards, invoices from Ebay or other online purchases, Copy of the title to a donor rig that you bought for parts and harvested parts off that might be the S-10 a guy buys and uses the chassis, motor and trans. Bill of sale, copy of the title and the papers from the scrap yard when you hauled the leftovers in if you gave them the title. Their whole deal is that you acquired the parts legally.
The rebuilt statement reads the same
https://www.txdmv.gov/sites/default/...les/VTR-61.pdf
Some forms wouldn't come up when I went through the list.