The part that is broken off is basically a stub with a threaded hole in it for the tiller handle mount. It is part of the crankcase casting, so you will either need to weld a piece on or replace the crankcase housing itself. I’ll see if I can dig up a pixel or two later.
Best,
PM T2
He's livin' in his own private Idaho..... I hope to go out quietly in my sleep, like my grand-dad did..... and not screaming, like the passengers in his car...