Britpart are known in the UK as "****part" and for a GOOD reason!!
The "quality" of their stuff is terrible, I've had bad experiences with them and I wouldn't fit anything bar a brake disc from them.
Someone spoke of the centre bearing, if that's on the rear propshaft, it's generally not a rebuilding item, I've not read of many people having success of splitting the shaft and then rebuilding it.
Mine went, while bearing had gone so I bought a new propshaft.
I know LR considers the driveshaft non-rebuildable and only sells it as a whole piece for $500 or something like that. I found my center support was bad the week before heading up to the Rubicon for a snow run last month and didn't want to spend the big money so I threw an aftermarket part in for 1/4 the price. As I explained, I worked under the assumption that due to the IRS the shaft would be under less articulation stress and that if if failed it would most likely be in the same manner as the stock part, meaning the center support which isn't a 'dead in your tracks' failure. But all these pics of snapped driveshafts is changing my mind.
I know people have successfully rebuilt them, but it's not a simple on/off. Now that I have some time I'm going to order a bearing ($90 at AB) and have at it.