FWIW, here are a few pictures of the sewer hose storage tube I installed recently. This was not an easy installation and you may find a better location for stowage of the hose. At first, I thought there was plenty of space for the 90 deg. ell between the propane tank and the dump compartment, but the ell was a little larger than planned; a tight fit, but it did fit.
On the plus side it is convenient to the dump outlet and is up out of the way. And, it beats stowing the sewer hose in a compartment taking up clean storage space.
The only materials locally available was 6" pvc sewer-drain pipe and fittings. It is light weight and easy to work. If 5" pipe was available, it would be a much better fit into the tight spaces along the frame. Not sure if 5" is available. I had to collapse the wall of the pipe to a slight oval shape along the length toward the blind end to fit it into the recess area that was available. The tube is 62" long not counting the inlet to the ell and can accommodate my 15-20ft. Rino hose and fittings. I had a similar setup on my other MH, but was much easier to install and had an open space for the tube.
Hope this helps with your hose.......oh, did I mention, this was not an easy installation?