55.2 rear frame Gas tank

[surfmurf]

Wish suggestions for a GOOD FIT for a '55.2 3100 rear frame gas tank mount.
1 - My initial idea was to mount a tank between the rear frame rails that has a right SIDE, front gas filler that I could duct to the original Cab gas filler cap. I intended to run the gas lines either inside or outside the driver's side frame.
I have not been able to locate a tank to do this with over the past about 2 years.
2 - If it is impossible to locate a tank for this design, then my next choice is a tank also for a rear frame rail mount for a rear license plate area fill tank and probably a step bumper.
Any ideas for an old man guys? Murf