thanks for the replies.
I would just replace the valve but my trailer has the underbelly sealed and the valve is up inside where I'd have to remove the plastic/cardboard liner to access it. I'd rather not do that.
I think I may add the Valterra twist on valve anyway but I don't want to just leave those existing valves blocked. I want them working as well.
I'll try Agesilaus' solution to flush the tanks and see if that helps.
I had wondered if I could just leave those valves open and pour water in from the top (down the toilets). If I leave the end cap in place but both of the partially blocked valves open, it should fill up the pipes until those valves site under water. If I were to leave that filled up for a day or so, wouldn't the compacted toilet paper just disolve naturally? (Maybe I'll add the water softener, etc. just in case there is some more unmentionable material in the blockage as well...)
Anyone see any reason not to try that?
