Hi Ken, I too wish to rearrange my mainsheet control and am in the process of looking at the various methods. My reason is to provide the room for some sort of shade as it is getting pretty warm here in Phoenix. Right now I am experimenting with a large Windbrella inserted into a pivoting fishing rod holder attached to the lower hatch board. If this doesn't work I may go to a bimini. I have talked to Joe Kidd and Fran Lebowitz who have both moved their mainsheet control to the aft end and are happy with the move. Based on reading the old files, some others have also made the move. If I am not mistaken both Joe and Fran simply added a fiddle block with cleat and swivel between the traveler and the aft block on the boom. While I haven't purchased one yet, it appears that the Harken Little Fiddle block (057 through 060) or the Schaefer #303-75 Fiddle Block with swivel shackle and cleat would both work. I am sure other fiddle blocks would work as well. I gather that a boom vang would probably be needed if the mainsheet is moved as the boom would be free to rise while going downwind. Evidently the Potter 15's have a mainsheet set-up similar to the M15 and while some of those folks have moved the controls aft as noted above, others have installed a Ronstan pivoting base block with C-cleat (WM 2002 catalog page 1008) to the middle of the boom and controlled the mainsheet from there. I don't know if anyone in this group has used this method but I would be interested in opinions as to how it would work on an M15. Best of luck on whatever you decide. Don Olson M15 Phoenix, Az.