Hey James - Thank you very much for the tire recommendation!!
Didn't realize how difficult it was going to be to find 13" LRR tires in the stock size! Also appreciate all your other tips ...
Looking at the progress of my current tank... ~250 miles at half tank... so target is still looking like ~50mpg...
I think what Clev said is correct... I'm thinking that on my very first ever fillup (back on 12/30), the station fuel pump might have shut off early, giving me a higher than expected first tank MPG result and then a lower than expected second tank MPG result (which is actually true... I was surprised how high the result of the first tank was given that the orig owner drove most of that tank and was claiming only 30 to 35mpg)... and now this tank is more in line with "reality".
Phew, I think...