A241e AW11 sc trans rebuild costs?

What sort of costs are involved with an a241e rebuild?

The box will engage gear but won't deliver power to the wheels. It's hard to tell if its the torque converter or the box. I've since done a manual conversion but have the provision to put the whole lot back to stock. Being a late build 88 (89 delivered) and in otherwise mint condition I would like the option to return it build plate standard; however if its going to cost an arm and a leg I'd sooner flog the box and shafts and cut my losses.

Cheers.