Why not buy another Briggs of approximately the same type? Please post some pictures plus your model, type and code numbers (stamped on the cooling air cowl) here, and also post the same information in a new thread in the Wanted forum.

Those synchro-balanced Briggs engines frequently run their balancer bearings due to being operated with dirty oil, or no oil, and even before they actually break, there isn't much can be done for them anyway (aside from promising yourself that you'll keep them full of clean oil in future).