Looking for a Sandwich Plate for a 1994 XJ12

My 1994 XJ12 has a severely damaged sandwich plate (aka upper oil pan, upper sump). Having done a thorough search of all my favorite parts sources, I’ve been unsuccessful in locating a replacement.
Does anyone here know of an available replacement sandwich plate for this engine?
Any help would be greatly appreciated.

Thanks in advance.

Supplementary information: The part number is EBC9699. This sandwich plate is different from the one used on V12 engines prior to 1994. EBC9699 was used for the 1994 - 1996 XJ12 and the 1994 on XJ-S. I do have the skills and equipment to TIG weld the plate, but I’m afraid of subsequent cracking of the welds (and the ensuing rapid loss of oil) and would greatly prefer to find a replacement.