Sounds like a condenser issue; the 135mm Rodagon should be fine for 4x5 printing. There should be a condenser lens in a housing above the negative stage, with a door that swings up so you can reposition the condenser. This door has a diagram on the inside that shows the position of the condenser for specific focal lengths.
That's very well explained.
"Often moments come looking for us". - Robert Frank
"Make good art!" - Neil Gaiman
"...the heart and mind are the true lens of the camera". - Yousuf Karsh