I agree...
If the toilet is still original, it's most likely a Mansfield 751 or 752, which was discontinued more than 20 years ago...no parts have been available for more than 10 years. If it's been replaced with a Jabsco, it's not worth repairing...a brand new one would cost about the same as the cost to repair. So either way, you need a new toilet...the only question is whether to replace it with another cheap (about $150) "disposable" toilet that's likely to need replacement again in a couple of years, or spend a bit more (about $250) for a toilet that'll last at least 20 years if you just keep it lubricated and put a "rebuild kit" (all the rubber parts) in it every 5-6 years. That would be the Raritan PH II, which has been rated the best manual toilet under $500 for several decades. The Cricket was discontinued a couple of years ago.You might want to check out the link below to learn how to operate and maintain your toilet and tank correctly.Btw, how did your surveyor happen to miss the leaky toilet? It's something that the seller should have had to replace.