Toilet replacement - Thetford or Dometic?

Rod10

Previous owners did not drain van down for winter and the toilet flush tank is cracked and leaks slowly. At least that's what I am assuming but I haven't taken anything apart to check...

The flush has now completely stopped working (fuse?) and I'm inclined to simply replace the whole thing because it's been problematic for a few years.

Can anyone tell me if the Dometic and Thetford toilets are interchangeable? I understand they are pretty much plug and play but am worried the header-tank filling door and waste compartment door might not line-up correctly if I put a more modern Dometic
(ceramic lined) toilet in where the existing Thetford currently sits.