well in that case I think your first diagnosis might be correct. I am not sure where the vane pump is the VE pump and whether it is a DIY job or not? if I remember correctly the internal pressure in the VE pump is something like 70 psi, so it...

Only to check and replace them one at a time after the fault occurred , so no mix ups .

Have you had theinj pump feed and return banjo bolts out for any reason?

Light hone/new shells/rings and stick it together, in the old days this was called a top and tail. I would defo fit new rings, bet you a coffee the old one have lost their twang! I took some out of a truck the other day and was amazed how much...

My series 2 tdi breaths like thomas the tank engine, still runs okay apart from the breathing, starts well, pulls well.

well if a hone and a new piston rings only gets you a year or two that might be good enough. The 200 can run okay even when well worn.

Turner engineering have new liner sleeves for 21 quid.

I reckon that might be the case. That bore damage looks like water damage? Was it breathing much before you stripped it? I would still try the hone first, you never know you might strike it lucky.

I would give it a light hone and see, but I think you may be on a hiding to nothing there.