Odd fuel gauge?

Hi all, my 05 TD5 90 has shown an odd fault today, I've only had it for a week but this morning the fuel gauge showed empty despite it having 1/2 a tank, it slowly crept back up to half way over 5-10 minutes. It did the same mid-morning, then this afternoon the needle shot straight up to half like usual.

If this persists, does it sound like a dodgy sender?

Also on a separate subject the clutch biting point is very low, it's been 15 years since my last defender and I can't remember if this is adjustable?!

Thanks, TC