I'm considering whether to repair or replace the toilet in my 40' Country Coach Allure RV. I've disassembled the toilet completely and am hesitant to replace parts in the base. I found a 510 pedestal kit for $$$ online. Is this compatible with the 510 Plus toilet model? Alternatively, purchasing a full toilet for $$$ seems more practical. Can you confirm if this toilet includes the gasket and mounting hardware for flange installation? Additionally, does it come pre-assembled when purchased as a complete unit? Thank you!