Not very much, I'm afraid. There isn't any build info for the 70s that I am aware of. There are some options that were added to the serial number as a suffix. The letter B at the end of the serial number meant wide front axle, or high clearance as they called it then, KD meant kerosene engine. There were more, but I'd have to look them up.

I will be doing a feature on the model 70 in the summer of 2010, since it will be featured at that year's summer show. It's not as far away as it sounds...