Had a 1991 Wanderlodge for a number of years. Bluebird made some great motorhomes and is one company I wished could have held their operation together.
Anyways your fuel problem brought to mind a trip we did where we had a tail wind and we drove from Atlanta to Fargo, ND before we had to refuel. The exit was a button hook and about 2/3's of the way around the engine started missing. Luckily it came out of it and we made it to the pump. I don't recall the exact amount in gallons it took to fill the 300 gallon tank, but I do remember it was a bit over $1100.00.
Mine had a Detroit 8V92. Good power but poor fuel economy..4-6mpg. When I sold it, it had over 200,000 miles on it, was still solid as a rock and ran like a top. If it would have had some slide outs I'd still be driving it.