Transfer box knacked.

Hi Guys, some of you will know that I'm a new user and am looking for a landy to convet to a 200di.
Just come back from looking at one, reasonably sound long wheel base job, a couple of faults one's the wiring which is not a major concern, the other is the fact that the 2wd/4wd selector is strapped to the bulkhead with a bit of flat bar, the owner says that it kept jumping out of drive.
Is this repairable with a service kit, whats likely to have gone wrong.
just trying to work out how much it'd cost to sort this out, I'm gonna have the box out anyway, but if its gonna be mega bucks I'll steer clear.

Ta.

ok been doing a bit of research,
the lt95 has a selector rod which has detent grooves and a spring loaded ball bearing, and as some have pointed out these wear, and in some cases the lever has just fouled on the body work preventing full engagement, causing it to jump.
One thing that really stands out though is one guy said that he had trouble with the box jumping out of high range due to incorrect diff ratio's front and rear, well this landy I looked at has a load of wheels in the back spare, and I suspect pretty much that the rims/tyres fitted are not all equal, this is gonna be the same effect is it as a different ratio diff front/rear is it?.
A simple fix then if nothings gone knacked in the process.
Sean.

looking in my manual it could be something as simple as adjusting the stop bolt immediately under the linkage where the lever passes through the pivot hole bracket , you could try this before you buy !

dont think the guy realises that its fairly obvious he's selling it because he thinks the box is knacked, wouldnt be a good time for me to sort it out.
its a 109 so the r380 would be a better fit from the disco, so I might just go ahead and do that, would the axles of the disco fit too, or is the susp totally diffo on the disco.
Ta.

iv done a post DISCO AXLES ON LEAF SPRINGS as im gonna have a ago at it have a look inthere see what you reckon

I've just mentioned disco axles on the same thread, and maybe I should have said this there but someone mentioned that the diff ratio is diffo on the disco, and I kinda got the impression that that was prohibitive, but now I've just found out that the diffs are transferrable, so fitting a diso rear axle is practicle.
But whats the diffo between a series and a disco axle, the only benefit I can think of is its probably cheaper and bits are more available.
Is therea n issue with brakes on the rear axle?