Driveshaft

Noticed leak from below gearbox on passenger side and think I have a leak from driveshaft seal also noticed a leak from speedo cable which was loose which I tightened up and now speedo is flickering . Should speedo cable have a seal has I think I have it to tight and what is best way to remove driveshaft . Thanks

Flickering speedo's are quit common, especially at lower speeds. Its caused by the cable not spinning freely in its casing. If its not too bad it might be easier to live with. Straight forward, if very awkward to replace. I'm fairly sure the speedo drive can only be removed when the gearbox is split, somebody will correct me if necessary. Even then it can be difficult to remove after a few decades of being in place. As far as I'm aware the speedo drive shouldn't leak just because there is no cable attached/loose.
The drive shaft seal can be replaced with the gearbox in situ. Unbolt the drive shaft from the gearbox output flange and then you'll need to lever the flange out, its held in place with a spring clip, again, can be reluctant to remove. Then just lever out the seal and replace. Access is awkward. Ideally you'd do all these jobs when the engine and gearbox is out for other work. All parts are easy to obtain from the likes of Eurosport X1/9 spares

Thanks mate