I replaced ours with latches from Walmart that cost less than a couple of bucks and were superior to the originals in our RT. Lowes or Home Depot have a big selection.
I didn't want an exact replacement because I thought the originals were inferior. I also replaced all the hinges on the overhead cabinets that the door swings up. The springs were so weak that I kept hitting my head on the open doors. I simply bought some 110 degree cabinet hinges at Lowes and replaced every one of those puppies a couple of years ago...........no problems since.
There are few things in our RT that were disappointing, but hinges and the latches on the toilet door were sure sorry things.