Sounds like you got pretty lucky. Given you saw no wear, and no metal shavings, in the oil, if it was me I would just bolt it back up and call it good. The other things I would look at carefully are the nut that holds the yoke in place, the splines in the yoke, and the splines on the pinion shaft. Make sure there is no damage to any, and see if you can find anything that would indicate why the nut backed off, ie the deformed threads on the nut are no longer deformed etc. Technically I think you are supposed to replace that nut after every removal, but when I just replaced the yoke on my Ford, I just inspected the nut and saw the treads were in good shape, and used a little red loc-tite. If there is any damage to the splines on the yoke I would also be looking really closely at the splines on the pinion shaft, the yoke should be a pretty snug fit to get on.

Sean