Hi Dave, I left the mr2 bits as they are and bought some stainless rod. Bent that into this shape:
This is for the drivera door. The right hand side slips snuggly into the sierra handle with two cable ties holding the vertical part, then three ties on the horizontal part to attach to the mr2 bar. Only provisionally held it all in place with cable ties. Will see if I can get some small bulldog clips or jubilee for a permanent fit. Not sure if you've noticed but the rear vertical part of the mr2 bar where it goes into the plastic enclosure has a lip on it. Initially, this was catching and stopping full deflection of the lever.
One door on, run out of clamps now.