It has been a while since I have been able to get on the trike and ride do to my MRSR infection, but I now have a clean bill of health. But I think the weather will still hold me back.
I have the seat mounted and made a few modifications to the mounting mainly as a precaution to protect the Carbon fiber seat. I mounted the seat in the following way. On the lower mount I placed a large fender washer over each mounting hole. Next on top of each fender washer I placed a 1 3/4" rubber Grommet with a smaller Grommet placed inside to reduce the inside diameter for the 8mm cap head screw. On top of that came another metal fender washer followed by a rubber washer. This raised the seat by 1/2" in the front but allowing more recline. On top of the seat first came a rubber washer then a fender washer. The screw had a plastic sleeve as thick as the Carbon fiber around the screw so when tightened the threads did not touch the seat. Below are photos of the mounts.