New to Defender 90 but the hi and lo gear stick became loose after previously being stiff before I bought the Landy. I put in lo ratio and it clunked in driving ok stopped out in hi ratio drove off fine then changing from 1st to 2nd the central diff selector underneath the Landy broke now does not go in any gear.

AA man got it to work on our narrow track road but only in 1st or reverse to limp home "..............

Any advice on what next and do I need a bank managers salary to fix it!

you need to take tunnel off and have a look lever been loose after been tight would suggest a break in linkage ,the housing with lever would need freeing and lubing, then jack one rear wheel up and adjust linkage to ensure it goes into hi/lo equally and the same with diff lock, the jacked up wheel allows you to rotate hand brake drum to allow selection