ORD Offroad makes a tail housing mod that will give to a speed sensor for the 205, bolt on option. You send yours in and they will install the parts.
As for leaking ATF, figure out where its leaking first. might be a seal or gasket.
I use Rightstuff as a gasket maker that stuff won't leak.
If it's leaking at the output yoke you can call ORD and see what the recommend.
sometimes you need a
skf speedy sleave kit.
Those guys know everything about the NP205.