The variator and tappets werent the problem so you agree with the wiltshire wizzard who said a week ago that it the big end shells,
He says if you've caught it early enough then you can get away with a simple shell and oil replacement which takes around 2 hours, on the other hand if the crank has ovaled but not more than 0.02mm then it can be reground, or you can take the risk and use the other bottom half and spend 2 days and loads more cash trying to build a good engine, aslong as that crank is fine, but even then he would replace the shells and rebuild the head to make sure the engine was sound, and if your in that deep then you may aswell replace the clutch. The Asda priced, 20 years experienced on marque, Alfa trained, liscensed aircraft technician says it would cost you around £60 to DIY the big ends before you need to think about pulling lumps out.... and the oil pumps are VERY reliable on TS engines.
Jack up and support the front end,
remove the sump to ancillery bracket bolt.
drain engine oil,
remove the ring of Ribe bolts round the sump,
remove the 2 x 13mm bolts from the gerbox sump join,
remove the 15mm bolt from the lower engine mount to sump, lower the sump slightly,
remove the 2 bolts holding the oil pump pick up pipe and the fully lower the sump,
rotate the engine by hand so that 2 big ends are at the bottom, remove a spark plug from each cylinder to aid engine rotation if you wish,
remove the end caps and shells and measure the journal diameter twice at 90 degrees, DO NOT PUSH THE ROD UP TOO FAR OR YOU'LL BEND VALVES.
if it's too oval then that's the end.
If it's ok then rebuild with new shells, oil pick up gasket (or a dab of sealant on the old one), silicone sealant and oil.