Texas is one of the few states that allow for BONDED TITLES on vehicles. I just went through a similar incident where I purchased a deuce from a someone that purchased it from GL. He never titled the deuce because he only used it on his ranch and never intended to put it on the road. He gave me a bill of sale and the original GL paperwork with his name on it. Texas DMV said he had to title it first and then sign the title over to me, and he didn't want' to do that because he'd have to pay the taxes and title fees. So I had to get a BONDED TITLE.
In Texas, if you purchase a vehicle and have a bill of sale, but no title, you can apply for a bonded title. It takes a little time on your part to jump through all the hoops, but it's not THAT bad.... You , have to take the truck to the Texas DPS Office and have the VIN verified (make sure it's not stolen), then you get a surety bond for the vehicle (the bond for my truck was $6000 and cost me $92). After the vehicle has been inspected and you have purchased the surety bond, you take the paperwork to the DMV and they will title it with a bonded title. The bonded title works just like the regular title, and after 3 years, you can apply for a regular title if you are so inclined.
The instructions are online, including the forms that you will need, or you can go to your county tax assessors office, and they will give you a packet with all the forms you need.