Classic/Antique Car Repair: 1950 Chevy Powerglide, transmission leaks, pan gasket

Question
I recently purchased a 1950 Chevy Sports Coupe with Powerglide in Montana.  When driving it home, usually at 55-60 mph I noted I only got 10 mpg.  Is this normal for the Powerglide?  If not is there anything I can do to increase the mpg?
Also, the transmission leaks, not a lot.  All bolts are tight.  
Thanks for any help you can give

Answer
You will need to check all of the regular tune up items including the vacuum advance unit on the distributor. With that said in 1950 we used to have a saying, "slip and slide with power glide." It was a two speed unit with a real power eating fuel economy eating fluid coupling. The interstate system was still a gleam in Eisenhower eye and the average highway speed was 45 miles per hour. Add to that the fact that the 6 cylinder engine was a long stroke design that made torque at low speed and was not terribly efficient at high speed. Fuel economy will probably not ever be this cars strong suit. As far as the transmission goes you might replace the pan gasket but probably the seals could use replacing after close to 60 years of service.
Brad