Micah,
I just look a quick look at the J. P. Beck's in RCA II. A lot of his guns apparently had no toeplate. There is one pictured on page 433, #98. The toeplate is short, with a symmetric round end with a little "leaf" on each side. It's held on with 3 nails. Shouldn't be hard to make one similar.
Kentucky Rifles and Pistols, 1750-1850 pictures the same or very similar toeplate on page 85.
-Ron