The piece I showed above is the only one out there it seems that includes the toe board as well as the rear seat pan. If you cut those pieces off and use a center section like the ones above, you can create a cat-car floor, thats what I had to do!
Like I said, if you want the toe board and don't mind taking the time/money, buy the Sherman board for the 70-73 that I showed above. You can get it from RockAuto for under $400. They have both sides available, all you need to do is use a center section from another pan that fits an 81, like those posted in post #20. Weld them together and your good to go, easy project. I'm in the process of doing just that right now, there are some pix in my build log here: