I finally got my "fat funky" seat for the '84 RM! Feels great! Changed the ergos perfectly to get rid of the RM Trench at the seat/tank junction. Can't wait to ride it.
Thanks to Beenridin for finding the shop to make these!
I don't remember the measurements, but it matches my RM465 and also a modern bike. For some reason the stock '84-85 RMs had a super low seat dip - very hard to ride.