71 swinger project

Hey everyone' I'm new to the forum and I just got a new 71 swinger project ( first mopar project) I started by assessing all the bad metal, all are common spots, but my swinger has rusted through on the rear seat floor pan by the LF frame all rot, the pan is also rusted through in the trunk. My question is is there anywhere I can find the rear seat pan (the floor pan that starts in the back seat to over the axle), because I can't find a replacement pan any where. Or am I going to have to frabricate patches where it rusted through. Any suggestions would be great. Thanks.