911 gearbox - rebuild, salvage, reconditioned ?

[nigel911]

Yesterday the gearbox on my 1983 911 SC eventually gave up the will to live - I lost the ability to select any gears and on opening the inspection plate on the underside of the gearbox we found a loose nut, metal shavings, etc.

I guess I have 3 options.
1. Rebuild
2. Replace with a reconditioned box
3. Replace with a salvage box

What are peolple's experiences/views?
What sort of costs should I expect?
Are there any specialists out there you would recommend - I am in Surrey.

I do not have the capacity, time nor ability to the work myself.

Many thanks