MT Audio Design XO-2001 crossover

Has anyone ever built a copy of an MT Audio Design XO-2001 crossover?

It was made in Sweden by Matts Tornqvist but is no longer available, the perfect crossover for the QUAD ESL-63/Gradient SW-63 set up.

I do not have the schematic but there are seven ICs in the subwoofer section and two in the main ELS section.

It has many useful functions, two of which are: a pot for setting subwoofer volume level and another (a delay circuit) for phase shifting the sub. A very elegant and noticable function.