I have enough Horseman frames and bellows to easily do 35"
Check B&H, they list Harmon DPP up to 50" x 50'. I have some 5x7 FB I will be shooting soon. Just got a 6'x2' sink, my darkroom is taking over. I have old Norman and Novatron's, 7 heads working. I have have light! Most likely I will convert my Levy Process camera to 11X14, right now the previous owner has it set up for single sheet 8x10. It does almost 35" bellows. I will make a lens board extension. Perhaps later I can add a 16x20 rear extension. I am not getting any younger, the time to do stupid things is now!