Great detail and great pics! I did Rt. 66 roughly from Santa Fe to Oklahoma City about 3 years ago and then continued through Arkansas to Memphis. I did my best to stay on Rt.66, even the unpaved sections. The rental car was filthy!
Interestingly enough, I had originally planned to start in Memphis and then drive west (late spring), airfare from/to the WAS area being roughly the same. The one way rental car cost, starting in MEM and finishing in ABQ, was outrageous. I checked a couple of other car rental agencies - same thing. I called my preferred agency and asked 'what's up with the pricing?'. Agent told me that the east coast customers took cars out west for the winter and it would be much less expensive if I were reversing the trip. So I did at about 30% of the originally quoted cost.