I like Kepharts and I would be curious what Spyderco could come up with. Maybe a folder in the ethnic series?
The defining feature seems to be a spear point with a centered tip. Many modern Kepharts only have that in common with the original. A kephart should also have a broomstick handle with a finger guard. Kephart was pretty specific about what he wanted in a knife and describes it in the book.
Considering that Spyderco has many leaf shaped blades I would say that Spyderco appreciates the utility of a centered point as much as Kephart did. Spyderco's ergonomic handles however do not have the versatility of Kephart's more basic handle. The Temp2 and Mule have leaf blades with centered points but the blade shape is a little different and they lack the handle neutrality of the Kephart. The Bushcraft has a centered point and a versatile handle but is not a Kephart either. That is probably as close as it gets though.
Here is a Becker BK62 with an original copy of Kephart's "Camping and Woodcraft". That book is over 100 years old! The BK62 is as close to the original as any knife you will find. Ethan Becker owns one of the only known actual Colchester Brothers Kephart knife and he modeled the BK62 after it. (The knife is mine but the book belongs to a friend)
Other Kephart blades. The Ontario Blackbird SK5 has a Kephart blade but a typical Ontario handle. There are also a 4.25" and a 5" Bark River Kepharts.
I used the 4.25" Kephart to field dress a buck this year.