Servowarm Elite 50 Boiler - ignition stopped working?

This model is obviously very old but until the summer was working perfectly. The ignition went and when someone looked at it he immediately classed it as dangerous and put a do not use sticker on it, as the "heat exchanger leaking water onto burner" and he said that parts were no longer available as boiler ws old. He of course recommended a new one. Does anyone know where I can get parts or is the engineer correct?