While flying over the Gramps last weekend I noticed that the ridge leading directly up to the Planetarium at Redman's Bluff has been substantially burnt out by fire.
This could provide relatively straightforward access from the 4WD track leading west off Mitchell Road (no promises though).
I haven't been to this crag, but have been to the close by Redman's bluff, which still has a fair bit of potential for new routes, and is nice and close to Melbourne. It definitly has an adventure feel to it which I like, and not many people go there.
Let me know if you are planning a trip to check out this (new) access and I might just come and help out. If we can establish a new and better track that could well simplify access to this crag.
From the write ups it got many moons ago it looks like it's worth a visit.