Ah, that looks like the first whip I had, well similar anyway, I'd say make sure the fall is the same width as the last three feet of thong, even a tiny bit thinner wouldn't hurt, that would make it more arrow dynamic.
And definitely having a good popper on the end tied on, something like six or seven inches long, what ever your preference, experiment and see what you like.
that whip should crack though, at the time , the insides of my first swivel handled whip was straw, no plaited belly, no nothing really, but it gave out a loud crack, particularly the side crack and overhead actually, it was 12 feet long.
Good times,
![Laughing :lol:](./images/smilies/Indy-laugh.gif)
.
All the best
Jim J.