I personally would find a new bowl, and also find out how to best preserve the existing one. I have no idea if they are heat cracks, or stress, or both.
I've seen meerschaum calabash bowls for sale in the after market. You will probably not find any Pioneers though.
I would just smoke the thing until it fails -- if in fact it does fail. The bottom tip of those bowls can get real tarry, and that may actually help to keep the bowl intact.