Alignments checks revealed that downstream end of TUDA was ~1mm off (can't remember which way).

Re-entrant flange (window end) found to be ~5mm too low and ~2mm to the left. Checked upstream end of chamber and was ok.

Removed bellows etc. and re-entrant flange, replaced with re-entrant flange bolts only figure tight. Tighten bolts from inside chamber whilst checking alignment, adjusting as appropriate.

Managed to get to ~0.5mm to the right and ~0.25mm too low.

This is acceptable so closed chamber and checked vacuum down to ~150mTorr.