Rob,
Buoyancy is something we all struggle with in hard lure making. That's why most builders use balsa for smaller baits, to get the maximum buoyancy and action.
Epoxy is relatively heavy. So is epoxy putty. Try to find a way to minimize the filler you need, and the size of the hardware you use.
I use screw eyes, and run them in and then back out, coat the threads with crazy glue, and run them back in one final time. I find the crazy glue reinforces the threads that were cut into the lure the first time, and lock the eye so it doesn't unscrew when a fish hits it.
If you're using basswood, it should be strong enough to hold a .072 guage 1" screw eye, set in crazy glue. Anything bigger or thicker just makes the lure heavier, without giving you any substantial gain in strength. With metal props at both ends, the weight of the hardware adds up quickly.
Try and keep in mind the fish you're targeting, and the line strength you're using. 8lb test will fail long before a 1" screw eye pulls out.
And a pike or muskie will probably bite through your line, or your bait, before the screw eye ever has a chance to pull out.
I wouldn't try to make a small, thin topwater like the Devil's Horse strong enough to stand up to those fish. By the time you get it finished, it'll lose all the buoyancy and action that make that lure work in the first place.
Good luck.
P.S. Really nice looking baits! Good job.