Here are some pictures from a seat restoration I did recently. The seat pan was cracked in several places. MIG welded the tears, had the pan sandblasted and powder coated, then reupholstered the seat with a reproduction cover.

Attachment 1758Attachment 1759Attachment 1760Attachment 1761Attachment 1762Attachment 1763

After welding and powder coat:
Attachment 1764

All done:
Attachment 1765Attachment 1766Attachment 1767