Yikes. The red top types were a good battery.
Odyssey makes a good battery also.
http://www.odysseybattery.com/
Guess we are all hosed. Lot's of stuff still runs 6v.... always a way. Guess I'll be looking into magneto ignitions.
Look at forklift and tractor batteries as a lot of them are still 6v.
http://usbattery.com/products/6-volt-batteries/