i searched on ebay and found a 2nd gen OBC listed. Also searched on car-part.com, but can't determine what exactly they have and if it is the OBC/DCDC unit. You can see the phone numbers for salvage yards and call to ask.
i would happy to try to repair your board if you wanted to send it out, seems a shame to get this far and not finish it. i order parts frequently and can combine other items to save on shipping.
Last year i bought 2 OBC units from Japan but they were the 2nd Gen with different DCDC boards, and the shipping cost more than the items, and i found a blown capacitor in the one unit that i opened, so that didn't really work out.