Left seems to be popular... I actually welded up my holes after I took measurements. I too have my "born with" keys and the dealer key chain. Very cool to have. Side note, I have one Rochchester Products key and one Briggs....
Most of the emblems were made by a company called D-Line. They offered similar designs to pick from, some decals, plastic, screw on and tape on...I have the Demo kit from them, I can post some pics tonight if there is any interest.
Steve