Thanks for all the replies.
Regarding the checking of levels of point frogs, if they are found to be proud, what methods are recommended for levelling, a) in situ (ie laid and fixed) or b) free reign?
For b) I would file off, well away from anything that wouldn’t like the dust, and finish with 320 grit up to 1000 to tidy up.
However in situ, the dust issue seems tricky if filing. Is shaving possible? A Dremel style tool would spread the mess everywhere.
If they aren’t proud, but sunk, can they be successfully raised, or does the whole thing need to be junked? I’m struggling to think of how to raise them without bending the whole unit in the vertical plane, which would surely cause running issues by crowning the running rails.