Sinpac,
Unfortunately I will not be able to make the vinegaroon, I live in a military barracks so that's a no-go Is there a big difference between the clear-lac and neat-lac? I just bought the neat-lac from Tandy Leather.
The cracking does make sense, the neat-lac made the practice straps hard as a rock (thank god I practiced these all first!!). I put it on a belt I made and it turned out beautiful, these straps though, not so much. I'm definitely going to get some of the Fiebing's oil dye like you mentioned.... Seems to be the way to go for sure.