Bucket seat floor bracket broke thru pan

Thanks. Was able to save about 70% of the broadcast sheet. The cars always been an automatic. So should I put a wanted ad for that section of the pan ? Only use a bench seat donor ... so when I put my bracket back over it it’ll be level ? How much overlapping with the donor piece should be done? What would take a lot of cleaning of the metal the butt weld or the tig weld ?