Tracy did use a Mazda starter but I cannot remember what model it was from, I do remember purchasing quite a few before getting the same as he used from his pile of parts when he designed the drive.
You could elongate the hole out on the mount plate to suit that starter. it wont affect the structural integrity, main thing to check is the starter engages completely without binding on the ring gear, as this was an issue with some starter models.
Your starter looks like its had a hard life already.
Andrew