Wow, Wilgepoort! what an awesome spot. Used to go there quite regularly at one point. We even had a few WUMC formal dinners there. What's access like these days?
A friend (Steve Dunnett) and I tried the crack a loooong time ago (like 8 years I'm guessing). If it's the same one I'm thinking of, it heads out on the right side of the main open book that Cabernet follows?
I recall Steve took quite a long lead out (quite pumpy and hard to place gear) when he pumped out and and took a screamer onto a bomber number 9 or 10 wallnut. We lowered off at that point with the intention of returning. I think Russ Dodding retrieved our nut on top-rope a while later (and gloatingly told us he was keeping the nut as booty!). Never been back since then.
Anyway, I'd be keen to hear if you manage to free it. It's bound to be a classic piece of climbing (probably in the 25 range I'd say). Ask Russ Dodding or Paul Fatti, they used to go there quite a bit.