Yes, when I sold a tractor for 6K in cash I asked the buyer if I could take some pictures (after he had it on his trailer). I wasn't so interested in pictures of the tractor, but of his license plate and his truck! I asked if he needed gas before he got back on the highway, and told him where the closest place was. He told me his route and where he'd stop for fuel. I immediately went to the bank to confirm the bills were legit. I was just covering bases if I needed to send law after him.
In 2012 I bought a new L3200 and built a cab for it. After about 6 years it was replaced by an older L4240. Two things relate to discussions in this thread. First of all, I had the buyer bring cash and gave him a bill of sale we both signed. It stated the known condition, that it was free ad clear and that the tractor was sold "as-is". We took 185 $100 bills into my bank and had the cashier count and deposit it right then and there.
With regard of a couple earlier posts - The age of a machine (in years or hours) doesn't need to affect the appearance or mechanical condition of a machine. A bigger factor is how it was cared for and maintained. Below are examples. The L3200 was about 6 years and 550 hours old when it posed with the new-to-me L4240 that was probably built early in the 2007-2013 Series 40 production , with just under 1,000 hours on it when I bought it. It did take almost a year of looking to find a nice Pre-DPF cabbed tractor, but they are out there.