Thanks, finally clear now what they are doing with the 2:1 terminating in the cleat on the mast! I also found this other thread using google rather than the forums built in search in case others are searching for the same:

http://www.catsailor.com/forums/ubbthreads.php?ubb=showflat&Number=19076

I wonder if anyone has a specific block they have had success with or estimated max loading required for the top block for the 2:1 in that configuration?