Hello everyone seeking help to build a N500g crossover

i am currently listening with my altec A7 with the original n500g crossover. (The existing n500g has a sealed wax poured over all the components, so i do not wish upgrade or replace the box)
Hence, i would like to build an identical n500g but with better components and wiring to replace my existing one, then keep my existing n500g as a backup.

Does anyone has the schematic diagram and component rating/values for the crossover n500g.
So that i will buy the components & build a brand new n500g. The variable potentiometer may be hard to get a exact replacement any suggestion? Also what better caps should i replace with?