Gas oven heated from the bottom I moved to a new place and I have an ancient gas cooker that I can't replace just yet. As the heat source is at the bottom of the oven (rather than the top), would a baking stone help even out the heat and help stop burning? 

I’ve found lots of information referring to the beauty of baking stones when using an oven with the heat source at the top but cannot find anything that helps me.
There isn't anything wrong with ovens heated from the bottom, many actually are. It's actually better that way because heat rises, if the element is on the top you'll get an oven that is hotter at the top than the bottom. 

With a baking stone the principle is the same no matter where the heat comes from, with the same benefits, just make sure that there's space for air circulation around the stone. Also, baking stones take time to heat up, so leave more time for preheating.