If one gas leak is dangerous then two gas leaks are very dangerous - we read from time-to-time about houses blowing up and falling down due to a gas leak. Death from Carbon Monoxide poisoning is also a hazard for you and any other people in the home - pets too. You should be worried.
A call to your energy supplier might be best.
As for a recommendation for a replacement gas appliance - nobody here knows your requirements or the size of the hole it has to fit into.
Take care...
Peccavi
July 2013