I think a picture doesn´t help you much because i have done modifications to that part of engine,but i remember there is nothing else but that triangle alum. piece.There was also a little generator for handle heater but you don´t need it.It was assembled in that alum. piece with three screws.If it leaks there
you must take it off and check/replace oil seal and o-ring inside of it.It´s important they don´t
leak,if they leak your engine never runs good.Check also there is no screw holes open to crankcase.You can get this oil seal and o-ring from all bearing stores etc.They are usual size.
You must also put something to keep the back bearing in place,otherwise the crankshaft may
move back when engine gets hot.I try draw some pictures to you,i hope they help.I am not
very good in drawings,this was first time at all when i try to draw with computer.....