When processing murals, I use a pair of cylinders that I made by cutting 5 ft. lenths of plastic drain pipe (1.5 inch works well) and gluing caps on the ends. They are light enough to float and are essential for lifting soggy fiber base paper out of a bath.
I just tape one end of the paper to one of the cylinders anddraw the paper acrass an 18 inch trough. When the first pass is made i wrap the wet end onto the other cylinder and roll it back. I use a diluted developer to achieve 6 or 7 minute developing times.
Good luck with the murals. Please keep us posted.
Jack