City/Gravity Water Fill Door

My access door is cracked and faded and corroded. I can find them well enough but it seems that the dimensions changed since I got my trailer. The rough opening is 4" x 6" but everything out there now is 4-3/4" x 6. Does anyone know a source besides Valterra and JR that has these things? Would like to avoid sawing on my trailer if I can.

https://www.ebay.com/itm/Valterra-A01-2000VP-White-Gravity-City-Water-Hatch-with-Door/162624818827?epid=1536959764&hash=item25dd31ce8b:g:Lv0AAOSwdjRbdBBX&vxp=mtr