*Level II will have a small label identifying the tire size and inflation pressure. It's located on the inside of the fuel door. It should say Level II on each side of the vehicle.
*Before buying my second Ranger new, I researched the timing chain issue (didn't want to buy a problem). What I learned and to this day, experience, was that 04+ have the components that endure (for nearly all people).
*I don't recall the exact timeframe on the final revision to the tranny case/valve body gasket, but it was surely well before 04 and IIRC it's like, 01 or 02. Again, I didn't want to buy a problem and after dealing with the manual tranny, I rejected level II's that had it.
*Somewhere after the 2005MY Ford replaced the OEM Bilstein shocks with OEM Ranchos.
*Rear end will not only have a Torsen carrier, but the axles are 31 spline (larger than what was used with the standard limited slip carrier). Because of this, the axle tubes will be larger than that of the non-Torsen rear ends. I don't know the size off hand, but if you like, I can go measure mine.
*On the level II, center bezel on the dash will be silver. Inst cluster will also have the same silver trim.
*You might consider taking the VIN to a Ford service department and see what work, if any was done on it under warranty. What I don't know is how long Ford will keep this data; maybe make a phone call first.
I have the showroom brochure for mine, this clarifies what was in the level II package. It would be very awesome if you could somehow get someone to scan and post the same but for a 2006MY. Ends speculation. For example, for my MY, all Level II's had black interior, carpet AND the rubber slop controlling floor mats. And oddly enough, mudflaps were only OEM on the rear end. I fixed that at the 1,000 mile mark.