I don't know if I could pitch that to my players (they;d find it too restrictive I think) but some combo of 1e, Osric and some of the Adventures dark and Deep Material would be a lot of fun.
As with my LL/S&W hybrid I'll use a background system instead of skills and my boon system when its done.
The Return of Planescape? - Curious. There is a brief note on this 'countdown' at Enworld.
3 hours ago