Thanks Bruce, I feel so stupid that I didn't check out the Transaxle pictures before posting about the brake system.
My Transaxle doesn't have that missing part and I worked out how to put it all back together.
The ride on is working as new now as far as the transaxle goes any way..
Now I need to look at shimming the front end a bit to tighten all the play in the steering linkages and to stop the wheel wobble and wandering steering.
Cheers