where can I buy a replacement engine/oil pan for honda gcv135-a2e?

I have a hole 1/4 inch diameter in the oil pan, can it be welded? if not where can I buy the replacement as Honda don't seem to make that model anymore? It is a honda gcv 135 4.5 engine. GJAFE-1095542-A2E. It is to fit a Mountfield 46cm p/d. Year if manufac 2001, motor 300RPM (product code MPR10071-01. S/N
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