Struggling to get up hills in 3rd and lacking power = a 2.5TD engine - mine is exactly the same - i suspect like mine oil blows out the breather pipe and iff you take the oil filler off you get a puff of smoke out if you rev it up - bottom line is prob needs new rings, valve guides (+/- valve regrinding), new big ends, new main bearings etc.........
Or a 200tdi engine?
I'm still trying to decide either get a 200tdi engine, or sell it to somebody who does not know what there like, and buy a newer landy (but then i will have to start at the begining in fixing up the rest of it)